Produced by Chuck Stevenson and Greg Fisher

[This story originally aired on March 10, 2018. Ir was updated on Sept. 8.]

Fabio Sementilli was a beloved hairstylist and beauty company executive living the good life in Los Angeles. That all ended when he was brutally murdered while relaxing near his pool. Why would anyone want to kill him?

After Sementilli was found stabbed to death, police scoured surveillance video from his Los Angeles neighborhood. Cameras caught the suspects on video running to his home – and then leaving in his Porsche 35 minutes later. While there was video, the suspects' identities are hidden.

"Fabio was bigger than life in the industry … he was the iconic guy … the international hairdresser that came to the U.S.," says colleague Pete Castellanos. Facebook

Sementilli was described as larger-than-life in the hairstyling industry. He lived with his second wife, Monica, and their kids in a beautiful home. At first, police believed Sementilli was the victim of a notorious wave of crimes known as knock-knock burglaries, targeting celebrities. Knock-knock burglars had hit the homes of former Los Angeles Lakers star Derek Fisher, Nicki Minaj and Alanis Morrisette. These thieves typically stole cash and jewelry, but this was the first case where police initially tied a murder to knock-knock burglars.

"It was at 9 o'clock … and I get a phone call and it was Monica … she was crying and distraught and she was saying, "They killed Fabio," Mirella Rota, Fabio's sister," tells CBS News correspondent Michelle Miller.

Police would learn that the reason behind the murder was much darker and twisted than a simple robbery. Turns out, it wasn't a break-in gone wrong that led to Sementilli's death after all. Nearly five months later, a pair of arrests would shake Sementilli's family to the core.

"It was like a twist in a nightmare," says Sementilli's son, Luigi.

LARGER-THAN-LIFE

When police found 49-year-old Fabio Sementilli, he was collapsed on his poolside deck. He had stab wounds to his face, neck and body.

Justin Eisenberg | Chief of detectives, LAPD [to reporters]: This is a particularly vicious murder. …this individual was murdered in his own home.

It looked like a textbook break-in. It was the end of the day. Fabio was relaxing by his pool.

Mirella Rota | Fabio's sister: He probably was out there enjoying his cigar … On the phone, speaking out loud. Didn't hear someone walking behind you.

Detectives quickly learned Sementilli had been a superstar in the world of hairdressing.

Mirella Rota: He was a happy man and he wanted everyone around him happy.

Luigi Sementilli | Fabio's son: The best way to describe my dad really is like a cup of coffee in the morning. …he gets you going … he lifts your spirits … he gets you determined to charge the mountain of life.

Michelle Miller: Did your friends say, "Hey Luigi, is that your dad?"

Luigi Sementilli: Absolutely, yeah. It was kind of a fun thing you know … it's hard to avoid him when you type in Sementilli on Google, it's very hard … in fact when you type in my name, Luigi Sementilli, the first thing that comes up is his profile [laughs].

Fabio and Mirella grew up together in Toronto, Canada.

Mirella Rota: He was my mother's son. … everything was about our brother. Sometimes … she'd have get togethers. … and she'd be like, "Fabio, what do you want to eat?" He says, "Ma, make your lasagna" … and we all had to eat lasagna…'cause that's what Fabio wanted to eat.

Fabio Sementill [video]: I didn't have a lot of connections in the industry. I did have my sister who was a stylist, but you know how it is with your sister and all that [winks].

Fabio and his sister started out as hairdressers.

Mirella Rota: And I would always try to run a really elegant salon, you know? …a salon where there's like a little bit of peace or an oasis and my brother's like, "Oh! Chill!" Like, "Hey, how's it goin'?"

Ten years after they started working together, Fabio divorced Luigi's mom.

Fabio and Monica Sementilli Facebook

In 1997, he married for the second time to Monica, a customer and makeup artist.

Michelle Miller: What attracted him to her?

Joe Mercurio | Fabio's friend: She was incredibly charming, she was attractive.

Michelle Miller: Good-looking woman?

Joe Mercurio: Right? Not bad, yeah. Definitely a good-looking woman …

Restaurateur Joe Mercurio grew up with Fabio.

Joe Mercurio We were kids, grew up on the same street … and I'd call his name out and his name was Ravioli to me.

Michelle Miller: Ravioli?

Joe Mercurio: Ravioli, yeah. I probably didn't know his name.

Mercurio was best man at Fabio's wedding to Monica.

Joe Mercurio: The wedding was incredible, we were dancing right to the very end.

Mirella Rota: We saw their relationship as a love story.

Fabio was also in love with his career. He and his sister Mirella were getting famous.

They became what's known in the beauty business as platform artists -- experts who demonstrate techniques, motivate other professional hairdressers and compete internationally.

Mirella Rota and her brother, Fabio Sementilli Mirella Rota

Mirella Rota: We would travel the world. We would be in Russia or in Germany or Italy and we would be up on podiums winning gold medals, just like being on top of the world feeling fabulous.

In 2011, Fabio's charismatic personality got him promoted to an executive position at the beauty giant, Wella.

He moved away from his sister Mirella in Toronto and took his whole family to L.A., where Fabio and his wife Monica settled into a life most of us can only dream about.

Michelle Miller: He drove a Porsche.

Mirella Rota: Yeah.

Michelle Miller: What man doesn't want a Porsche in Los Angeles?

Mirella Rota: You're absolutely right…

Fabio and Monica lived in a million-dollar home, where they were raising two teenage daughters, Gessica and Isabella.

Fabio Sementilli [video]: My own family unit is most, most dear to me.

Fabio led a charmed life until that day on Jan. 23, 2017.

Joe Mercurio: Tuesday morning, my wife tells me there's a phone call early in the morning from L.A. … and I'm in disbelief, saying, "What, what, what?" And then when I went online, I saw the police in front of the house [in tears].

Fabio's attackers had ransacked his bedroom and stolen his Porsche.

Suspicion immediately fell to the knock-knock burglars -- those gangs of crooks who hit fancy L.A. homes--- mostly stealing jewelry and cash from celebrities.

They even hit the other Fabio -- Fabio Lanzoni -- the cover page guy from romance novels.

Fabio Lanzoni [to reporter]: They pretty much took whatever was there.

Det. Bill Dunn | LAPD: I worked gangs for a long time and these guys are gang members.

Los Angeles Police Department Detective Bill Dunn has hours of videotape of the "knock-knock" burglars in action all over wealthy Los Angeles neighborhoods.

One video that he showed "48 Hours" comes from a home just seven miles from Fabio's months after his murder:

Michelle Miller: They seem to know what to look for.

Det. Bill Dunn: Right, they're looking for jewelry. They're looking for cash.

Michelle Miller: Look at him!

Det. Bill Dunn: Yeah, see he's checking clothes, he's feeling the clothes to see if somebody's put jewelry or cash in some of the pockets.

In the video, the burglars find the safe and pull it out of the wall.

Det. Bill Dunn: … he tells his buddy, "Hey, look at what we've found." ...Now look how many seconds -- and this is a real heavy safe … but they're very determined. They put a lot of effort into it and it's so heavy he can't -- he can't lift the thing. But look at how he's just gonna slide that thing out.

Knock-knock burglars are seen on surveillance carrying a safe stolen from a home in the Los Angeles area. LAPD

Michelle Miller: So they got the safe, that's pay dirt, and off they go.

Det. Bill Dunn: Yup! You see? They're gone.

Homicide detectives were hoping that there would be some surveillance video to help them solve Fabio Sementilli's murder -- and there was.

A neighbor had cameras pointed at the street just down the block from Fabio's house.

Det. Justin Eisenberg: At approximately four-fifteen in the afternoon on January 23rd, two individuals were observed jogging towards the victim's residence.

Two men in hoodies are seen running towards Fabio Sementilli's house the afternoon of his murder Surveillance video

In the video, two guys wearing hoodies can be seen running right toward Fabio's house. It's the right time of day.

And then 35 minutes later, they can be seen making their getaway in Fabio's black Porsche.

It turns out Fabio's house also had a set of outdoor cameras, but when detectives went to look for the video -- they were stunned.

UNDER SURVEILLANCE

All over Los Angeles, upscale homeowners have been installing very sophisticated video surveillance systems.

Navid Solouk: More and more houses are installing this kind of security cameras.

Navid Solouk is a home video security expert. While he didn't work on Fabio Sementilli's home, he set up a high-tech system for "48 Hours" in another house.

Police say it was Monica who arranged for a company to set up her phone so she could watch a live feed of the cameras around her house. "48 Hours" asked surveillance expert Navid Solouk to demonstrate how that would work by setting up a high-tech system for "48 Hours" in another house. 48 Hours

Michelle Miller: How many views do you get?

Navid Solouk [referring to a monitor]: Here you have six. You can go … up to 16.

Michelle Miller: Sixteen?

Navid Solouk: Sixteen, 32 -- so you can go up there with as many cameras as you want.

Navid Solouk: This is the backyard. If somebody is, say, walking through the backyard trying to get into the house, everything is being surveilled and everything is being recorded. So they can easily go back and see who was passing by.

Michelle Miller: What controls it?

Navid Solouk: So the camera signal goes to the DVR.

Michelle Miller: Where's that?

Navid Solouk: You got the DVR, its all being recorded.

Michelle Miller: So this runs the whole shebang.

Navid Solouk: This runs the whole shebang. This is the brain.

Michelle Miller: But without [the DVR]?

Navid Solouk: Without this, nothing.

The system Solouk set up for "48 Hours" is similar system to the one Fabio Sementilli had. Cops should have been able to grab the video and maybe ID the suspects.

But when police went to look for the back-up video, it was gone. The physical thing – the black box, the DVR -- it vanished from where it had been hidden in the garage.

Pete Castellanos | Fabio's colleague: You almost had to know where it was to take it. …Not knowing who did this, you're thinking, you know, could have been a specialized team of burglars, right? …wow, professional, this was a professional job.

And there was something else. The knock-knocks had never killed anyone. This was new and people were afraid.

Mitch Englander | Los Angeles city councilman: We put together a special task force in January of 2017.

Mitch Englander [driving the volunteer citizens patrol vehicle]: I'll take you down a street that we've had one or two knock-knock burglaries on. And you'll see how quiet this is and how away from the public. This is what they're looking for.

Englander and Miller notice a woman with a clipboard walking in the neighborhood.

Mitch Englander: Sometimes they'll wear a vest and look like a utility worker or carry a clipboard so they sort of blend in the neighborhood.

Michelle Miller: Would she be a possible --

Mitch Englander: Yeah, you got someone that wearing headphones, and a backpack carrying a clipboard.

Mitch Englander: OK, so this is a great example. She walked up to the door carrying tape, carrying flyers. She's got missing dog posters in her hand.

Michelle Miller: Really…

Mitch Englander: That's very, very suspicious … they're doing things like that.

Michelle Miller [to the woman with clipboard]: Hi, what are these? Can I have one of those? What are these?

Woman: It's … [inaudible]

Michelle Miller [reading flyer]: Certified pool pump replacement. OK, thank you.

While the councilman patrols and the community is on guard, Fabio Sementilli's family mourned his loss. Monica took center stage at the memorials:

Monica Sementilli: How lucky am I to have lived the greatest love story of all time, a story that people only read about, a story that movies are made of.

Elyse Bleuel was a friend of Monica's.

Elyse Bleuel: He was the love of her life …. And I couldn't imagine the grief that she was feeling.

Michelle Miller: What happened the day of the murder?

Elyse Bleuel: That night, at about five-something, I got a text saying … "come to my house. I need you."

Elyse Bleuel: There were fire trucks outside of her house and I was like oh gosh … there was no police yet. It was just the first responders.

Elyse Bleuel: It was her and her daughters sitting in chairs in a row in their dining room.

Elyse Bleuel: She just kept saying that "he's gone," that "I'm not a wife anymore."

Elyse Bleuel: I just held her. I just held her.

Elyse Bleuel: It was so painful, just the weeping, the not being able to breathe. She was beyond devastated -- beyond devastated.

Elyse Bleuel: We must've sat in there for 10 or 15 minutes and then the first round of police came and asked us to leave the house and go outside.

Michelle Miller: Had you seen the body? Had you seen --

Elyse Bleuel: I didn't … I just wanted to be the best possible comfort … I didn't know how to comfort that … she couldn't speak in complete sentences until like the fourth day.

And as weeks passed with no arrests, Fabio's sister says Monica grew more anxious.

The cops weren't saying much of anything, so Monica started calling them every day.

Michelle Miller: What did she want to know?

Mirella Rota: …if she was maybe shaking hands with the murderer right now? If she was, "I could literally be shaking hands with the murderer of my husband." …overall, upset about the fact that there were no leads.

Michelle Miller: What did you see that being?

Mirella Rota: Desperate.

Monica may have been desperate and frustrated but, around her, people were starting to ask awkward questions.

For example, if the knock-knock burglars really were running wild and they were suspects in Fabio's murder, why would Monica and the kids continue to live in that house?

Elyse Bleuel: It was assumed that it was a couple guys that had jumped the fence and it was a robbery.

Pete Castellanos: I was hearing about break-ins. I was hearing about home invasions.

Pete Castellanos: And that's -- I don't know if I would stay in that house.

Luigi Sementilli: I had trouble even walking in that house again.

Mirella Rota: I feared for them. I wanted them to have surveillance. I wanted them to have security guards and she didn't want any of that.

And something else seemed strange.

Luigi Sementilli: The only thing I thought that was unusual was why didn't they take more? Why didn't they take his watch?

The suspected burglars left an $8,000 Rolex on Fabio's wrist.

Pete Castellanos: As time goes on, you're thinking -- was there something that was goin' on that we didn't know about?

A BIG BREAK

It was a big secret. Nobody except investigators knew it at the time, but there was blood on the scene that didn't belong to Fabio.

That meant they had DNA to work with.

Capt. William Hayes | LAPD: We were able to develop forensic evidence. Some of that was DNA, which identified Robert Baker.

Robert Baker 48 Hours

Robert Baker is a name you will hear a lot from here on out.

He had been a racquetball league director at a Los Angeles gym not far from Fabio Sementilli's house.

That's where Elyse Bleuel met him.

Michelle Miller: How would you describe Rob Baker?

Elyse Bleuel: He was cool. Um, we all really liked him.

Elyse Bleuel: He was one of those gym guys, you know, grrrr [growls].

Bleuel played in Baker's racquetball league.

Elyse Bleuel: He was very alpha. He was a very alpha male. There was also a kind of a sexual-ly thing about him.

Michelle Miller: There was something sexual about him.

Elyse Bleuel: You know how some guys just have just have this sexual kind of, I don't know – he was very manly … he was in shape and he was kind of, you know, kept everything -- he was in charge.

Elyse Bleuel: I think I knew that he had been military police.

It turns out Rob Baker was a man with quite a colorful past.

He'd been in the Army. Then he got tangled up in the porn industry. Bleuel heard about Baker's movie career from a friend who happened to spot him in an adult film.

Elyse Bleuel: That's like the kind of gossip … you just need to tell someone.

Michelle Miller: Who did you tell?

Elyse Bleuel: [Laughs] I told Monica.

Monica Sementilli, Fabio's wife, was also in Rob Baker's racquetball league.

Michelle Miller: What was her reaction?

Elyse Bleuel: Well, it was pretty anticlimactic, I'll tell ya.

Michelle Miller: Really?

Elyse Bleuel: Yeah. 'Cause a lotta times when we would have girl talk she'd get a little prudey (sic). Like a little prude.

Cops were sure Rob Baker was connected to the murder. After all, they say his DNA was at the crime scene.

And, as it happened, Baker's DNA had been in the police database for years. He is a registered sex offender.

Capt. William Hayes: Robert Baker has a 1993 conviction out of a Long Beach case -- it's for lewd and lascivious acts with a minor.

Police say Baker served time for that offense against a 14-year-old girl. But what was his connection to Fabio's murder? Was Baker a knock-knock burglar?

For months, police watched Baker. They tracked his movements and his phone activity and they discovered two things: first, he was not one of the knock-knock burglars; and second, he made hundreds of calls and texts, to, of all people, Monica Sementilli.

Det. Justin Eisenberg | LAPD [to reporters]: Over the past several months, investigators have developed information and … identified Robert Baker, 55 years old of Canoga Park, and Monica Sementilli, 45 years old of Woodland Hills, who is the wife of our homicide victim, as responsible for his murder. LOCAL NEWS REPORT: This community in shock – 45-year-old Monica Sementilli under arrest now on suspicion of murdering her husband and being held without bail.

Elyse Bleuel: My instant and thorough and complete reaction was there's no effing way. There's no effing way. She loved him, he was the love of her life … there was just no way. I was there. She was decimated.

Mirella Rota says she and Monica Sementilli were like sisters. Mirella Rota

Mirella Rota [in tears]: Twenty-some years of my life she was like a sister. She was a cool aunt to my kids … she was loveable, my whole family felt that way about her.

Mirella Rota: It's just too painful to think that he loved her so much and that she may have a hand in this. It's very painful. Hard to digest.

DAMNING EVIDENCE

LOCAL NEWS REPORT: Female anchor: Police believe the hairdresser was alone when two men broke into his home. Male anchor: It appeared that the murder had occurred during a home invasion robbery. LAPD press conference: Monica Sementilli and Robert Baker were involved in an intimate relationship that has predated the murder and it looks like they were together for approximately a year-and-a-half.

Michelle Miller [to Mirella Rota]: So police come to you. Oh my god … never in a million years you said would you have imagined this woman to be involved in the murder of your brother. So what convinced you she was involved?

Mirella Rota: Time. A little bit of time. In the beginning I thought there would be a shadow of a doubt. But then she had no bail. And then the indictment.

Mary Fulginiti | Former federal prosecutor: It's a very detailed outline of the plot to commit murder.

Mary Fulginiti, a former federal prosecutor, took a look at the criminal complaint for "48 Hours."

Mary Fulginiti The charges here are capital murder with special circumstances … and then the second charge here is a conspiracy charge … for the two of them to commit murder.

Michelle Miller: What is their motive? I mean beyond wanting to be together? …what were they after?

Mary Fulginiti: It's money. I mean, it's sort of like this is like the oldest crime in the book. I mean really, it's two lovers obviously wanting to be together and then wanting to get rid of one of the spouses for money, and then here it's a life insurance policy. And he had about approximately $1.6 million life insurance policy that they were hoping to cash in on once he was gone.

Police say Monica Sementilli and Rob Baker tried to stage the murder to make it look like the work of the knock-knock burglars and throw the cops off their trail.

Mary Fulginiti: They staged it to be a burglary. You know, they ransacked the master bedroom as if they were looking for something, and then stole the Porsche.

News report: They say his black Porsche was stolen and used as a getaway car.

Fabio and Monica Sementilli Instagram

To begin with, six months before the crime, Monica Sementilli and Rob Baker allegedly came up with a plan to spy on her husband Fabio.

Michelle Miller: Who do you think the D.A. believes is the mastermind?

Mary Fulginiti: Monica.

Michelle Miller: Why?

Mary Fulginiti: Monica's the one who, six months before the murder, made sure she had the right access to her surveillance video system. Monica was the one that fed all the information to Baker so that he could have access to the video system. Monica, according to the prosecution, is the one who showed him where the DVR was so that he could remove it from the house.

Police say it was Monica who arranged for a company to set up her phone so she could watch a live feed of the cameras around her house.

"48 Hours" asked surveillance expert Navid Solouk to demonstrate how that would work.

Navid Solouk: …we can just simply download the software and connect to the camera remotely. You connect to the DVR remotely and just go on the camera, any of the cameras that you want, and view each one.

Michelle Miller: So I can view it?

Navid Solouk: That's right.

Michelle Miller: Could I send this to someone else?

Navid Solouk: As long as you've basically given them the information about the DVR with the password, another person can easily get in and just have the same exact view.

According to police, Monica shared everything with Baker: her password, her IP address, her username -- even the instruction manual for the system.

On the day of the murder, police say both Monica and Baker were using their phones to monitor the Sementilli home surveillance system.

Michelle Miller: Is there a way for them to detect when she was logging into the system?

Mary Fulginiti: Yeah. If they have their phone and they have the information from their phones they could see her trying to access it.

According to the D.A., Monica and Baker met in a remote corner of a Target store parking lot just two miles from her home. It was like something out of a crime movie.

They allegedly began to stage an elaborate alibi. For Monica, it was making sure she'd be away from the home and would be seen shopping first at the Target, and later at a supermarket.

But police says Monica was following all the action.

Mary Fulginiti: All the while, monitoring the surveillance video system remotely so she could see what was going on.

Detectives allege that both Monica and Baker used the streaming surveillance to be sure the coast was clear.

Police believe Monica actually stayed away from her home until her youngest daughter, 16-year-old Isabella, came home.

Isabella discovered her father's body.

Joe Mercurio: I can't understand how a human being can inflict pain to their children. It's counter-nature and it's something that I can never understand.

Michelle Miller: What's the most damning evidence against them?

Mary Fulginiti: Yeah, with regard to Baker, they've got a smoking gun. They've got his DNA at the scene of the crime and that DNA happens to be blood … With regard to Monica, they don't have a smoking gun, they don't have her at the scene of the crime, and they don't have her, you know, obviously, involved in the physical act of murder -- so they've got only circumstantial evidence against her.

Remember, Monica was clearly not home when Fabio was murdered. And she was outspoken in her grief for him:

Monica Sementilli [at Fabio's memorial]:He aspired to be the best person. …He has given us unconditional love and made all our lives an adventure.

She also went on social media putting up pictures and posts. But, according to police, that was all for show. They say at the very same time she was posting those messages, Monica was "having sexual relations with Robert Baker in a Las Vegas hotel room."

Mirella Rota: It confuses us, thinking about how this could be possible, feeling deceived.

But Fabio's sister thinks there's more to the story.

MISSED CLUES?

Mirella Rota: You had an executive husband. You had two beautiful daughters, you had a grown-up stepson, you had a beautiful home, you didn't work, you had cleaning ladies, you had pool people, you had cars, money -- you had it all.

Mirella Rota [in tears]: She took away so much. We don't know who else to blame.

Fabio Sementilli Instagram

Mirella Rota thinks there may have been some clues about Monica that just about everyone missed.

It begins with the move to Los Angeles. Fabio was definitely becoming the "Big Daddy."

Mirella Rota: Fabio was definitely growing and his personality was getting a lot bigger. And she kind of took a little bit more of a step back.

Mirella Rota: He'd be like, "What are you wearing you hair like that for?" And she'd be like, "Well, what's wrong with my hair?" And he's like, "No, I don't like your hair like that. Let's do it like that," and she would sit there and let him do it.

Michelle Miller: Really?

Mirella Rota: Yeah.

Monica shared that she wasn't entirely happy in L.A.

Mirella Rota: I've had conversation with Monica where she felt that way. Of course, Fabio was 100 percent into building his relationship with Wella. But for Monica, she said she was a bit lonely.

It couldn't have helped that Fabio was on the road all the time with a big new social life.

Joe Mercurio: Fabio was a very worldly individual. And for obvious reasons he travelled quite a bit. He saw a lot and he had an incredible capacity of connecting with people. That's what made him incredibly special is his capacity to connect.

Joe Mercurio: Not to mention he was incredibly charming. … So imagine the individual that he was.

Monica stopped working, her kids were growing up, and Mirella began to notice changes just weeks before Fabio's murder.

Michelle Miller: You went out to L.A.

Mirella Rota: The one thing that I noticed when I was there … I noticed she was drinking a lot more. And she was smoking a lot more and she wasn't cooking as much and I know she loved cooking.

Michelle Miller: How much more was she drinking? What was normal drinking?

Mirella Rota: Let's say between 5 and 9 o'clock she'd have a glass of wine.

Michelle Miller: So was it earlier in the day?

Mirella Rota: Yeah, as early as 11 o'clock.

Michelle Miller: That was a signal to you something was wrong.

Mirella Rota: Yeah.

And then, two days before he was murdered, Fabio announced he was going on a "boys only" 50th birthday golf trip.

Mirella Rota: All I want for my 50th birthday is to golf with my buddies at pebble beach. It's a dream come true for me, and he said, "I'm sorry girls, no girls this time" [Mirella in tears] "I love you, but this is something I want to do with the guys."

And there may have been other hints. Two years before Fabio's death, Monica apparently confided her unhappiness with the marriage to a friend.

Pete Castellanos: She shared something with my wife that I thought, "well that's interesting."

Michelle Miller: What was that?

Pete Castellanos: One night at dinner she just said, "I don't like it here. I don't like the U.S., I want to go back to Canada. I'll leave and they can stay behind."

Michelle Miller: Without her husband?

Pete Castellanos: Without her husband.

But what friends and family found really strange looking back, was something Monica did right after Fabio's murder. She invited her alleged lover and co-conspirator Rob Baker to join the mourners.

Rob Baker and Monica Sementilli were photographed together at Fabio's wake 48 Hours

Michelle Miller: You did meet him.

Mirella Rota: I did.

Michelle Miller: Where?

Mirella Rota: On the Saturday there was a wake at the house … and then, about a half an hour later, I saw her back outside again with a drink, smoking and talking to this guy.

One guest even snapped pictures of Monica and Baker. You can just make out a bandage on Baker's finger.

Luigi Sementilli noticed the bandage too.

Luigi Sementilli: Robert and Monica were in the corner talking to each other ... sort of away from the party and that he had bandages on his hands.

Rob Baker was photographed at the wake held for Fabio Sementilli at the hairdresser's home. A bandage can be seen on the index finger of Baker's left hand [inset]. 48 Hours

Monica's friend, Elyse Bleuel, tried to make sense of it all -- she imagined dozens of scenarios.

Elyse Bleuel: Rob needed money and Monica, you know, had money and Rob probably seduced her and messed with her mind and convinced her. And she was --

Michelle Miller: Wrapped up?

Elyse Bleuel: -- caught up in this and we had all sorts of theories.

Monica Sementilli and Robert Baker are currently in custody in Los Angeles. They both have pleaded not guilty. As of now, they are being tried together.

Leonard Levine | Monica Sementilli's lawyer [to reporters]: The only relevant question is whether my client had anything to do with the death of her husband and that she adamantly denies.

And there's one more loose end in all this. Police say there was a third person involved in the murder. Remember the surveillance video of the joggers hidden by hoodies? Police say one of them is Rob Baker. Police sources tell "48 Hours" they believe the other person is an associate of Baker's but they haven't found him yet.

In the meantime, Fabio's friends and family are left to grieve.

Joe Mercurio: I just know that my friend … my dear friend, my best friend, is no longer available to me and I to him.

Michelle Miller: So what do you do now

Joe Mercurio: I say a prayer almost every night, to be honest with you.

Michelle Miller: Praying for what?

Joe Mercurio: Praying that he's somehow still smiling or tries put a smile on his face … I want him to smile again. I want him to smile again.

Luigi Sementilli: Most of all, I want people to understand how great he was, that he was a great man and that he deserved a lot better than what he got.

As for Mirella, she just keeps remembering back to the time Fabio and Monica moved to Los Angeles.

Michelle Miller: Did she make a promise to your mother?

Mirella Rota: Yeah. She told my mother that she was gonna take care of my brother. Before they left for Los Angeles … my mom said, "You take care of my son" and she says, "Don't worry Maria. I'm gonna take care of him."

The knock-knock burglars continue to hit homes in Los Angeles.

The trial of Monica Sementilli and Robert Baker is expected to be next year.