Diane Dennis: What was rather hopeless at first too is they just had no clues on what had happened. They didn't have anything to go on, you know. It was just a terrible feeling.

But then the investigation seemed to stall. Far away, in Salt Lake City, Utah, Joan's family waited for news. And waited.

In fact, there was no trace of DNA evidence found on her body, nothing to indicate her attacker.

Alan Rozansky: The manner in which she was clothed-- she had not been raped.

But there was something significant, a potential clue, in what was not done by the murderer.

Alan Rozansky: She was about 70 or 80 feet from the bike path and another 20 feet into the brush. Keith Morrison: And she had been strangled? Alan Rozansky: That's correct. Yes, she was.

A volunteer had joined a search party organized by Joan's husband. The volunteer called out the alert. He'd found a body. Detective Alan Rozansky arrived soon after.

And so the search was called off. She wasn't to be found. But of course--she was.

Alan Rozansky: We really didn't know-- Keith Morrison: You didn't know whether she was---alive or dead. Alan Rozansky: We had no idea.

They scoured the area with ATVs and search dogs but they could not find a trace of Joan Diver.

Sheriff's deputies beat the bushes up and down the eight-mile stretch of the bike path.

The news of the mysterious disappearance of a middle class professor's wife, a mother of four, was no small thing in Buffalo.

Which was strange because, when they came here and looked for the car, it wasn't there. They found it three miles away.

When sheriff's deputies arrived, Steven Diver told them he'd been searching up and down the bike path for his wife. He went far longer than the usual two and a half miles she usually ran. In fact he told them he'd also seen his wife's SUV with a full bottle of water on the console at the entrance to the bike path.

(911 call) 911 operator: Buffalo police 911. Steven Diver: I called before about my wife being on the bike path. And she is somehow out there. 911 operator: Oh she hasn't returned? Steven Diver: She hasn't returned but she's probably injured. And I saw her vehicle at the bike path. We're going to drive out on the bike path and find her because she's out there.

It was later in the day when Steven Diver learned Joan had not picked up their son from day care. He called 911.

Linda Tanner: I asked her, "Is it a safe place?" and she says, "Oh, it's really safe. People go there all the time." She says, "There's a wooded area. I don't go up to the wooded area." We talked about if someone tried to grab us what would happen. And she says, "Oh, I'd give him a fight." And I said, "Oh, I would too."

What Joan Diver wanted, on a fine September morning in 2006, was to see the children off to school, drop the youngest one at daycare, and drive down to her favorite run: the long path that winds through one of the safest towns in America. "The bike path," they call it here.

Linda Tanner: She had a very strong personality. She knew what she wanted and she went after it.

Her older sisters remember growing up with her, the baby of the family, back in Salt Lake City.

Diane Dennis: She'd been a runner for a long time and she was just trying to stay in shape.

Once there was a young family here in Buffalo, N.Y.; a transplanted chemistry professor named Steven Diver, his four children, and their mother - his wife - Joan Diver.

"I just remember there being a sense of fear," says Lissa Redmond.

Not far from the tourist shops that ring the thundering falls is a long quiet path that snakes through the City of Good Neighbors, bucolic, green, sweet -- and sometimes deadly.

There was just one thing that, all along, had bothered detective Rozansky. Something about the way Joan was killed.

Alan Rozansky: Double ligature marks around her neck.

It got a feeling going in his gut. It reminded him, eerily, of an old case that had haunted Buffalo for more than 20 years: the bike path rapist, a man tied to nine rapes, including two murders.

But it couldn't be. After all, Joan Diver had not been raped, and besides, the last they'd heard of him was way back in 1994. The case had never been solved. The man was probably dead by now or in jail.

Alan Rozansky: There were similarities to the bike path rapist, but we were not absolutely sure at the time whether it was not a copy-cat or just another homicide.

It was November, six weeks after Joan's murder, when a strange DNA result came in.

It came from a spot, a speck, a whiff of something human swabbed from the steering wheel of Joan's SUV three miles away from where her body was found.

Someone had been in there.

(Sheriff's press conference)

"There's some shocking information that this case is tied to other known cases … the Joan Diver murder tied to the bike path rapist."

It was astonishing where that microscopic piece of DNA would lead, its powers of revelation even then stirring unseen fates in a prison cell far away.

But not yet. Fates, as you'll see, have a way of brewing for a while. For the moment what jumped out hard and clear was something truly morbid: Joan Diver had been killed on someone's anniversary.

Alan Rozansky: It was the date of the Linda Yalem death, which was in Amherst back in the '90s.

After 12 years of hibernation, was Buffalo's bike path rapist announcing his return?

Buffalo was a giant once, whose rail system, the second biggest in the world, hauled steel one way and finished goods back again. But times change, promise fades, Buffalo's railways languished and became, in modest resurrection, bike paths.

Now, like some almost forgotten ghost, after a 12 year absence, he was back.

The old, failed investigation coughed back to life and the cops re-opened the frustrating old file that puzzled them for more than 20 years. They had the assailant's DNA, but he was still out there lurking in the paths.

There's a story around here, could be true, that a statue of David was cast as a direct copy of the original by Michelangelo. And there's the bike path, running right past it. This is a very public place and yet here is where, more than 20 years before he killed Joan Diver, police believed the bike path rapist struck for the first time.

Det. Lissa Redmond: 44 year old woman who was jogging, raped and strangled in such a way almost every blood vessel in her eyes was burst, horrifically strangled and left on the path.

Remarkably that first rape victim in 1986 survived, as they all did at first. All of the women were attacked in the morning, in broad daylight.

Det. Lissa Redmond: Victim number two, 17 year old girl raped and strangled as well with the double ligature.

Detective Lissa Redmond was all too familiar with the bike path rapist's resume from her work at the Buffalo Police sex offense unit.

Det. Lissa Redmond: The next victim was a young girl on the railroad tracks in Buffalo.

And there were more survivors to find.

Denise Foster: He told me to get down on the passenger side of the floor

Denise Foster still carries ligature scars on her neck almost 20 years later.

Denise Foster: Put the rope around my neck, and just held it. And he told me if I moved or if I screamed, he would pull it tighter.

The rapist took her down to a wooded creek-side. He forced her down onto a rock and stripped off her clothes.

Denise Foster: That's when he raped me and strangled me and just left me there.

Keith Morrison: You remember it getting tighter, and then

Denise Foster: Yeah.

Keith Morrison: You blacked…

Denise Foster: Yeah, I blacked out.

When she regained consciousness, she says, she stumbled naked into the road, where a neighbor saw her and called police.

Six rape victims survived and then on Sept. 29, 1990, the violence escalated. The bike path rapist became a killer.

(WGRZ news report)

"Linda Yalem's body was found yesterday along the Elicut Creek bike path in Amherst. The 22-year-old U.B. sophomore had been training for a marathon."

The bike path rapist killed again in 1992. Police found the body of 29-year-old Majane Mazur, a prostitute, discarded beside the railroad tracks.

In 1994, he struck again, raping a 14-year-old on her way to school.

And then he simply stopped, disappeared -- until 2006 when he killed Joan Diver on the anniversary of his first murder.

(WGRZ news broadcast)

"Ironically her disappearance and death came 16 years to the day Linda Yalem was killed on the Amherst bike path."

Now there was a new urgency to solve the 20-year cold case.

So for the first time ever, four police departments -- the Buffalo police, police from neighboring Amherst, the state police and the county sheriff joined in a special task force to find the man now who had been preying on women for more than 20 years.

Detective Dennis Delano is a cold case specialist with the Buffalo police department.

Dennis Delano: If I have to turn over every rock we can. We're going to exhaust all possibilities to get to the truth.

But every task force member knew this:

Dennis Delano: That the Diver homicide was linked to the other crimes. If we solved that crime, you have to solve the rest.

For years, law enforcement had known that DNA evidence from seven rapes, and now, three murders were left by one man. But who?

FBI profilers said that the bike path rapist most likely worked at night. And what investigators knew now from modern DNA analysis was that the killer was of Hispanic origin. But what struck Delano was his m.o., the distinctive signature he left.

Dennis Delano: All of them had double ligature marks on their neck. A lot of them were told to put an item of clothing over their face and eyes.

Then, as detectives worked through the yellowed old files, Delano came across something very strange: a completely different file of rape cases which occurred in the same place, by the statue of David, a few years before the first known attack by the bike path rapist.

Dennis Delano: We wound up making a spreadsheet on all of the crimes. And they're all basically identical. The only difference that we could find was that a gun was used or a knife in the first set of crimes. And ligature was used from 1986 to 2006.

But here's what made that case so strange: somebody else was convicted of the earlier crimes near the statue of David.

It was a young man named Anthony Capozzi, although he wouldn't be so young anymore. He had already been in prison for over two decades.

Back in 1985, Capozzi was 29, a schizophrenic who lived at home. One of the five children of Mary and Albert Capozzi. Anthony was asleep, said Mary, when the police came to get him.

Mary Capozzi: He said, "Ma, don't worry. I'll be back." Because he figured he didn't do anything, you know, that he'll be back.

Capozzi was convicted of two rapes and sentenced to 35 years in prison.

The Capozzi family watched as the authorities took Anthony off to prison.

Albert Capozzi: Oh, my god. It's-- tears you. Every day-- every night when you go to bed, you think of what's happened to your family.

Every day Mary prayed. Every week, Albert and Mary drove to whatever prison Anthony was being kept in. For 22 years. Five times he came up for parole. Five times, was denied.

Keith Morrison: You know, they did offer him a chance to get out. All he had to do was confess.

Albert Capozzi: He wouldn't-- wouldn't do that--

Mary Capozzi: His younger brother said, "Damn, Anthony, tell them you did because they'll get you out earlier." He said, "Why should I tell them when I didn't do it?"

And now, after 22 years, members of a task force looking for the bike path rapist and killer found themselves staring at the Capozzi case with brand new eyes.

Dennis Delano: A lot of the mannerisms that the perpetrator was doing were all identical in all the crimes.

Keith Morrison: What sort of mannerisms?

Dennis Delano: When he was leaving he told them to wait a certain amount of time. "Give me 20 seconds to-- or 20 minutes to-- to get away." Or, "Give me ten minutes to leave. Give me five minutes."

When Delano and the others compared the rapist's crimes with those of Capozzi, it made the hair stand up on the back of their necks.

Dennis Delano: The truth didn't match the circumstances. It just didn't jive.

The detectives were convinced that it had to come back here. In fact, to this little area right around the statue of David, to that bit of brush right on the other side of the bike path. Supposedly they were two separate cases. But why hadn't anybody noticed that the location of the crime was exactly the same, that the method used was virtually identical. These crimes had to be the work of one man.

Maybe the trial transcript would offer some solid evidence that those rapes attributed to Capozzi were somehow different than the others.

Dennis Delano: There was no other evidence linking him to those crimes other than eyewitness identification.

Was it possible Capozzi was sent to prison for crimes committed by somebody else?

Alan Rozansky: That's when we took a ride out to Attica correctional facility to interview him. It didn't take long to talk to him to know he wasn't the type of person that could do heinous crimes.

Their job was to catch a rapist and killer -- Joan Diver's killer -- not to fret about an old resolved case. Still, they put together what they'd learned about Capozzi and took it to the district attorney.

District attorney Frank Clark told the detectives there wasn't much his office could do.

Frank Clark: The law requires hard evidence. The statute is very, very clear as to what's required in order to overturn a jury verdict.

So the detectives followed their instincts. Perhaps rape kits, slides of evidence from the Capozzi case stored in the vaults of the medical center would have traces of DNA and that might exonerate Capozzi.

Lissa Redmond: We had hoped the Erie County Medical Center had some slides. And we're told there was no such thing.

No DNA. No proof of anything. So Anthony Capozzi stayed in prison.

Dennis Delano: It wasn't-- it wasn't a good feeling. It's sickening.

Meanwhile, in the search for the bike path rapist, detectives seemed to be stymied.

Lissa Redmond: Now we have our serial killer rapist out there and an innocent man in jail. So we-- all of a sudden we found ourselves in the middle of two investigations.

And that's about the time they discovered, in the old Capozzi file, a clue.

Alan Rozansky: And I said, this is our guy.

In the months after Joan Diver was murdered by Buffalo's bike path rapist, the task force manhunt produced two bizarre discoveries in a case file that had been gathering dust for more than 20 years.

One: the possibility that Anthony Capozzi, a convicted rapist, was an innocent man. And two: a clue, buried in the old Capozzi file, that had never quite been tracked down.

Alan Rozansky: And it was involving a rape many years ago, and a rape victim possibly in-- it was in the Anthony Capozzi file, because possibly they suspected Anthony Capozzi of that rape.

Keith Morrison: When did that rape occur?

Alan Rozansky: 1981

And what was the clue, tucked away in the file? A license plate number from the back of a car, given to police by a woman who reported she was raped by the car's driver.

Dennis Delano: We came across the fact that the victim had spotted her attacker two or three days after the attack. She was pretty sure, at the time, it was her attacker.

She took down the license plate number. At the time, way back in 1981, the owner of the car had an alibi.

But now, when detectives checked again, it turned out that owner had been hiding a guilty secret all those years.

He wasn't in the car. But someone he knew was.

Alan Rozansky: He said, "Detective, you're looking for me." I said, "Yes, I am." He said, "Is this about something that happened many years ago?" "Yes." And I didn't even pry. He supplied. He goes, "My nephew, Altemio Sanchez was driving the vehicle."

Sanchez. Remember, DNA had revealed the bike path rapist was most likely of Hispanic heritage. So could this Sanchez be the man they were searching for?

Dennis Delano: We took Hispanic names that were previously investigated and narrowed those down through state police resources, which ones were arrested prior for prostitution. Because FBI did a profile years ago. And said that most likely, the suspect frequents prostitutes.

There were 84 names on the list, and one of them was Altemio Sanchez.

Alan Rozansky: And I said, "This is our guy."

Was he? This Altemio Sanchez had been arrested twice in Buffalo for soliciting prostitutes. But that was years and years ago.

Alan Rozansky: Well, we decided that we were going to surveil Altemio Sanchez to get a DNA sample for him. Because we decided, we pow-wowed amongst all of us and said, you know, if we knock on his door and say, "Can we have a DNA sample?" he's going to say, "See you later, goodbye." And now he's going to be looking over his shoulder.

It was a Saturday night when they got their chance. Sanchez took his wife out on a date to a restaurant. This was the moment to find that hard evidence. DNA evidence. Investigators asked the waiters at the restaurant not to touch the couple's glasses when they left.

But would the glass, or napkin, yield enough DNA for some kind of identification?

Investigators rushed the glass and the napkin to the forensics lab. And then the wait began.

Lissa Redmond: It was like waiting for a baby to be born. We were literally hovered around the phone.

And? It was him.

(News broadcast)

"It's the break that law enforcement and people living around the Clarence bike path have been waiting for."

The official announcement was, perhaps understandably, colorful.

(Press conference)

The monster that's been known as the bike path rapist has been taken into custody.

Sanchez, 49 years old, was charged initially with two counts of murder in the second degree. He pleaded not guilty.

And in the hours and days after his arrest, all of Buffalo watched -- both horrified and astonished -- as they learned about Altemio Sanchez. Who was he really?

Was it actually possible a man of his standing and reputation could have committed such awful crimes?

In the city of good neighbors, it turns out that the suspected bike path rapist and killer was just that -- a good neighbor living among them.

(WGRZ news broadcast)

Male neighbor: He's a fantastic guy. (crying)

Female neighbor: Honey. They're the most wonderful family. We-- we just love then dearly. They have just been the best neighbors anybody could want.

It was simply beyond imagining. Altemio Sanchez, accused of raping and killing women for decades, was a regular guy who lived a quiet, middle class life in a Buffalo suburb.

Female neighbor 2: I never would imagine the bike path rapist murderer was a house away.

Altemio Sanchez, 49, had owned his house for years. He'd held, also for many years, a steady and respectable job working the night shift at a brass factory.

Lissa Redmond: Like any family on any suburban street. He was always the first one that signed up for the, you know, charity things, and volunteered to help out.

Sanchez's family, said police, including his wife of 25 years, had no idea, not a clue, until the headlines and news reports brought their whole world crashing down.

Lissa Redmond: No. She was absolutely dumbfounded.

How could it be? The man finally arrested after more than 20 years of brutal attacks, rapes, murders, the ugliest of human behaviors, turned out to be a married, church-going dad, and a little league coach whose players knew him, with affection, as uncle Al.

When the investigators interviewed Sanchez, they were confronted, they said, by a wall of self control and denial.

Alan Rozansky: Yeah, he was dancing a lot. He was probably preparing this for years.

Keith Morrison: And he didn't crack.

Alan Rozansky: No, he did not crack.

But, with that solid DNA evidence linking Sanchez to those seven rape cases and three murders, there was little chance he was going to walk, said district attorney Frank Clark.

Frank Clark: In the public's eye, when you have this DNA which takes the probabilities to the tens of billions, I mean the public just assumes DNA, that's him, guilty. Case over.

And the citizens of Buffalo and the suburbs of western New York let out a collective sigh of relief. Or at least, almost all of them did.

Denise Foster saw it on TV.

Denise Foster: When they-- the news showed his face, I just like went into stone. I knew it was him--

And the torment flooded right back.

Keith Morrison: How did you know?

Denise Foster: I remember the face

Keith Morrison: It was that clear?

Denise Foster: Yes.

Keith Morrison: Did it bring it all back to you?

Denise Foster: Yes

Twenty-two years later, said Denise, the terror lingers. The rock, the rape, the strangulation, the blackout, the naked stumbling for help. It doesn't go away.

Even the physical scars are still there, around her neck.

Denise Foster: I've had nightmares.

As the investigation continued, the task force discovered that Denise was just one of many in a growing list of casualties.

There were more victims than anyone had suspected, beginning, investigators now believed, in the late '70s.

But as they put together their case for the trial of Altemio Sanchez, a second obsession gripped the members of the task force.

They believed that an innocent man -- Anthony Capozzi -- had been wrongly convicted of two of the rapist's crimes.

Dennis Delano: I knew he was innocent and he was in jail. And I felt that we had enough circumstantial evidence to create a doubt that he was guilty.

That belief was not shared, however, by the D.A.

Frank Clark: I don't have any quantitative proof, like DNA, where we can look at it and make a determination. Dennis Delano: We found that it's a lot more difficult getting somebody out of jail than it is putting them in jail.

Since he couldn't get anywhere with the D.A., Delano went public and spoke with WGRZ reporter Scott Brown.

(TV interview)

Delano: In my mind, one person committed all the attacks … A lot of the verbiage, which I can't really get into, was similar in most of the cases. Scott Brown: He's like Andy Sipowicz [detective from "NYPD Blue"]. And he wouldn't let go of this thing.

Capozzi's sister, Pam Guenther, saw Delano's appeal on TV.

Pam Guenther: I was shaking. I said, "I cannot believe this. This is our angel."

She called her parents -- Anthony's parents.

Keith Morrison: You didn't know what was happening?

Mary Capozzi: No.

Albert Capozzi: I didn't know. She says,"Mom, what would you like-- the best thing you could have?"

Mary Capozzi: We said "Anthony, naturally."

And try as they might, detectives on the task force just couldn't find the hard evidence that could undo what they now firmly believed was a gross miscarriage of justice.

So as the trial of Altemio Sanchez approached, they wondered: would two people wind up in prison for the very same crimes?

Delano: I mean it's-- that's not right, though. It's always been my understanding that if something's not right, you try and correct. Not just overlook it.

But even Delano was going to be shocked by the impending discovery.

This summer, after more than 20 years, Buffalo celebrated the revival of its bike paths.

Altemio Sanchez had already decided not to wait for his day in court.

The number of rapes attached to his name had mounted to 15, along with three murders.

And investigators had discovered something truly creepy.

Here on the roster of runners in a race commemorating the victim of the bike path rapist's first murder was the name Altemio Sanchez, wearing bib number 679.

It was on this last anniversary of that very same murder that the rapist spent the morning killing Joan Diver and spent the evening at a party with his wife.

Dennis Delano with Anthony Capozzi at a party celebrating release

This past May, four months after his arrest, Altemio Sanchez -- without explanation -- agreed to plead guilty to three counts of murder in the second degree. The statute of limitations had run out on the rape cases.

His wife attended his court hearings and visited him in jail. According to sources, she was unable to get her husband to tell her what he did or why.

But that isn't the whole story of course. What about Anthony Capozzi, in prison 22 years for supposedly committing two rapes?

Dennis Delano: The district attorney's office is telling us that we need hard evidence to free Anthony Capozzi from prison. Even though we knew -- beyond a shadow of a doubt in our hearts that he was innocent.

Then, suddenly, there was news.

At this building, the Erie County Medical Center, after years of misinformation, officials revealed a remarkable discovery: the rape kits, the swabs, the slides of evidence collected in the Capozzi case were there after all.

There was DNA. Tests revealed the rapist was not Anthony Capozzi. It was Altemio Sanchez.

And that's how it came to be, that on a fine spring morning, Mary and Albert Capozzi, now in their 80s, gathered their family around them after 22 years and phoned their son in prison to tell him.

(Phone call)

"You're free Anthony. You're free! They made a mistake." (Anthony Capozzi on the phone)

"All right. That sounds good to me." Albert Capozzi: It was really a miracle--

Mary Capozzi: A miracle.

Anthony was 29 when they took his freedom away.

Mary Capozzi: He said, "Ma, don't worry. I'll be back." Because he figured he didn't do anything, you know, that he'll be back. But he came back 22 years later.

In all those years in prison, he continued to suffer from schizophrenia so he was released to a psychiatric center, where he's getting help adjusting to an independent life.

Lissa Redmond: The family invited us to the psych center where he was released to after jail and when we saw Anthony Capozzi for the first time as a free man, there were no words. There were no words. Alan Rozansky: When he saw me at the psych center, he goes, "This is for you. I remember you." It's a piece of candy. He goes, "This is for you." So I keep it in my pocket.

Keith Morrison: Let me see that. Dennis Delano: It's been the apex of my career. I mean I-- there's nothing that I can compare it to. There's no feeling like that.

Now there was one more thing to do. On Aug. 14, 2007, Altemio Sanchez, the bike path rapist, appeared in court for sentencing.

(Altemio Sanchez in court)

I just wanted to mention that whatever sentence I get today, I deserve. I know I'm going to be spending life behind bars, never to see the streets again. But I committed, I did these crimes and I should pay for these crimes.

He will. The sentence was 75 consecutive years in prison.

The Capozzi family has a photograph that occupied the place of honor in the their house for 22 years. His parents decided they just couldn't take another family photo with Anthony in prison.

Mary Capozzi: I said, "We can't because there's one missing." I said, "The next time we take a photo, we'll make sure Anthony is in it." I said, "Some day we will."

And that's exactly what they did.

Thanks to the Buffalo News for use of their photos and headlines.