After that, we can’t know exactly what happened. But Anthony Amore , the Gardner Museum’s security director who took on the responsibility of investigating the heist in 2005, has pieced together motion sensor data for what’s believed to be the best approximation of what happened that night.

In the early hours of March 18, 1990, the city of Boston was still celebrating St. Patrick's Day. Two thieves dressed up in police uniforms and, at 1:24 a.m., simply rang the bell. The night security guard on duty, Rick Abath, let the two men in the Palace Road entrance. Abath called the second security guard on duty that night, Randy, back down to the desk. (Randy spoke to us on the condition that we only use his first name.) Then the would-be police officers handcuffed the two guards, and tied them up in the basement of the museum.

The heist of the Isabella Stewart Gardner Museum is something like the holy grail of art crime — and remains so even 28 years after it happened. In a little under an hour and a half, two thieves stole 13 irreplaceable artworks from the Boston institution. This podcast will explore why not a single piece has been recovered and if, after all these years, the case could be solved. But first, we’ll take a closer look at what happened that night.

First, the thieves made a beeline to the Dutch Room, in the southwest corner of the museum just off the stone steps staircase, on the second floor. There, they took all four Rembrandts off the walls (though they left behind a large self-portrait the artist created). The thieves also took Vermeer's "The Concert," a landscape by Govaert Flinck and a Shang dynasty gu (or beaker).

The thieves spent some time in the Short Gallery, a narrow slip of a room diagonally opposite the Dutch Room on the second floor. They took a bronze eagle finial, and five sketches by Edgar Degas.

Édouard Manet’s “Chez Tortoni” was the 13th piece stolen, removed from the walls of the Blue Room. It was the only piece stolen from a gallery on the first floor. But, according to Amore, there was no alarm in the Blue Room that night — and nothing about the theft of that painting matches the theft of the other 12. “It’s almost as if it were two different heists because the M.O. is different," he said. "They’re not similar except that they happened the same night.”

After 81 minutes inside the museum, an extraordinarily long time for an art heist, the thieves exited through the same door they came in by 2:41 a.m.

It came as a shock to the museum's director Anne Hawley. She was barely six months into the job when this happened.

"It was overwhelming to see what had been done. I mean to trash a museum like that. It was just like the barbarians had been through. I mean, to pull frames off the wall and shatter the glass, it was clearly not people that loved art that did that. I mean, cutting paintings out of frames. I mean, it's unspeakable."

For Hawley, who retired a few years ago, the loss of the paintings were akin to having a death in the family.

Subscribe to our newsletter for the latest updates, join our Facebook group to discuss the investigation and if you have a tip, theory or thought, we want to hear it.

This episode was adapted for the web by Amy Gorel.

Transcript:

ANTHONY AMORE: We're in a strange place. Many people don't come up here. You might have to duck a lot. We're in the attic.

KELLY HORAN: It's an unseasonably warm October day in Boston. The attic at the Isabella Stewart Gardner Museum is stuffy and dimly lit. Anthony Amore, the museum's head of security, has something he wants me to see.

AMORE: We're going to go around this corner here.

HORAN: At 6-2, Amore has to walk doubled over beneath the slanted eaves. We are high above galleries once ransacked by thieves in a daring overnight robbery almost 30 years ago. The attic space is dominated by a massive HVAC system. Its hum proof that it's working to keep treasures on the floors below at just the right temperature and humidity level.

AMORE: Almost there.

HORAN: We step out of the low amber light into much cooler air and quiet. I think this is what Amore has taken me to see: a storeroom of the sumptuous textiles used on furniture and walls throughout the Gardner Museum. But that's not why we're here. In the back of the room, in a space barely wide enough to accommodate us both, Amore puts his cellphone's flashlight on and pulls a plastic cover off something big. Oh wow.

AMORE: We're looking at the rosewood stretcher that held “Storm On The Sea Of Galilee,” but what you're looking at here is Rembrandt.

HORAN: So this is what was left behind after the thieves slashed "Storm On The Sea Of Galilee" from the frame.

AMORE: It is.

HORAN: When thieves slashed "Christ In The Storm On The Sea Of Galilee" from its frame with something razor-sharp, like a box cutter, they left behind the edge of the painted canvas attached to the stretcher underneath. It was Rembrandt's only seascape. In it, Jesus, serene, rises to calm a raging sea aboard a fishing boat that is being battered in a mighty gale. Alongside Christ's apostles is a face we recognize. It's Rembrandt, gazing out at us. In a letter dated Aug. 30, 1898, to her Florence-based art dealer, Isabella Stewart Gardner wrote: “Your description of this sea picture makes me fairly ache for it.” I think I know what she means. I've only seen copies of the painting but even those capture human frailty and the fury of the ocean. I can't imagine what it would feel like to stand before the original. But here I am, with a stretcher that once held it. It comes up to my shoulders at 5-feet 3-inches high and it's 4-feet 2-inches across.

HORAN: Wow, it's enormous.

AMORE: Yeah, you can see why they wouldn't have been able to take it with them.

HORAN: No, it wouldn't have been something you could carry out, but there is — that is paint that Rembrandt put there. What a thing to see. It kind of takes the breath away. In addition to that remnant of Rembrandt that the thieves left behind, they also left a clue about how they stole the priceless painting.

AMORE: If you look closely here you can see the cut into the stretcher. You see that?

HORAN: Oh, yeah. So they were pressing hard, with something extremely sharp, because it's a very clean cut.

AMORE: Right.

HORAN: Well, it's a crime scene, really.

AMORE: It is a crime scene, yeah.

HORAN: It's like the chalk line of the body, at the murder scene.

AMORE: It's a victim.

HORAN: It is. It's a victim. I don't know why, but it makes me feel very queasy to look at.

AMORE: It does, yeah. I get the same feeling every time I look at it you get. There's so much to it. It's Rembrandt so you're in the presence of greatness, right? But you're in the presence of history, too. This is the stretcher that held one of the most valuable things that was ever stolen. Why am I this close to something Rembrandt had? I'm from Providence, there's no Rembrandts, or stuff like this. You know it's just this awe-inspiring thing. I got to get it back — because this is torture. You almost feel like, why, why did I get stuck with this? You know why — because it's, look at it, right. You understand. I can never walk away from this.

HORAN: From WBUR Boston and The Boston Globe, this is Last Seen. I'm Kelly Horan.

JACK RODOLICO: And I'm Jack Rodolico. For the last year and a half we've been investigating the holy grail of art crime — the still unsolved robbery of 13 artworks from the Isabella Stewart Gardner Museum. It remains the world's greatest art heist with a haul valued today at half a billion dollars.

HORAN: We've gone behind the scenes of the investigation with the Gardner Museum's lead investigator and we've tracked down sources who have never before spoken publicly about what they know. We've worked closely with The Boston Globe's Steve Kurkjian, who has covered the Gardner heist for more than two decades. And we've gotten our hands on letters and a private diary, secret recordings and police reports that have never before been given a public airing. We've mined all of it in search of new insights into this old case.

RODOLICO: Because, after 28 and a half years without one arrest or a single recovery of any of the stolen art, we wanted to know why hasn't this case been solved?

HORAN: And all these years later, with suspects dead or dying and memories fading, can it be solved?

Each of the 13 pieces stolen on March 18, 1990, was last seen on the walls and in the galleries of the Gardner Museum. Picture a four-story, 15th-century Venetian palace that's been dropped into a leafy Boston neighborhood. In Venice, the view through the Gothic arched windows would be outward, at the Grand Canal. At the Gardner, the stunning view is inward, of a courtyard lush with flowers, palm trees and ferns. This palace museum was created at the turn of the 20th century by the Red Sox-loving, convention-flouting, 5-foot 2-ish force-of-nature Isabella Stewart Gardner.

Mrs. Jack, as she was known, shunned interviews, but she loved making headlines. She had her detractors, but her admirers shouted the loudest. An item in a Boston newspaper in 1875 referred to Mrs. Jack as "one of the seven wonders of Boston. There is nobody like her in any city in this country. Everything she does is novel and original. She is as brilliant as her own diamonds and is as attractive. All Boston is divided into two parts of which one follows science and the other Mrs. Jack Gardner."

When that was written about her, she was only 35 years old. It would be another decade before she would make her mark as a serious art collector when she inherited a fortune after her father died. In the meantime she was an avid collector of fascinating people. Many were young, beautiful, creative men. And she was a philanthropic force in a city that was becoming the Boston that we know today. But art was to be her driving passion. Toward the end of her life, Gardner wrote to a friend: "Years ago, I decided that the greatest need in our country was art." And so that is what she left, and among the artists that she gave us were the big men on canvas: Rembrandt, Vermeer, Manet, Degas — and the thieves went straight for them.

RODOLICO: Rembrandt's only seascape, one of only 35 or so Vermeers known to exist — not one of these stolen works has come back, not even after the museum doubled the reward from $5 to $10 million. Not the bronze eagle finial that sat on top of a silk Napoleonic flag and not the oldest piece taken — a 12th-century Chinese bronze gu, or beaker.

HORAN: All 13 works gone, along with the thieves. Nothing about what went down in the early morning hours after St. Patrick's Day on March 18, 1990, fits the Hollywood-fueled mind's eye notion of a museum heist. There were no cat-suited burglars repelling from the ceiling and snaking under laser beams. There was no elegant art-loving zillionaire who commissioned the theft so that he alone could enjoy the art from inside his fortified lair in some exotic far-flung locale. There was nothing elegant or art-loving about the Gardner heist at all.

RODOLICO: In the early hours of March 18, 1990, the city of Boston was still celebrating St. Patrick's Day. Hangovers would be widespread come daybreak. So would news that the city's most unusual museum had been the victim of a daring overnight robbery.

NEWS CLIP: Good evening, I'm Kasey Kaufman and here's what's happening. A priceless collection of artwork was stolen early this morning from Boston's Isabella Stewart Gardner Museum.

NEWS CLIP: It was 1 a.m. Saturday that two men posing as uniformed policemen fooled security guards here by claiming to be investigating a disturbance.

NEWS CLIP: Initial estimates put the value of the stolen works at at least $200 million.

NEWS CLIPS: The 87-year-old Gardner Museum is considered one of the finest small art museums in the country.

NEWS CLIP: Officials say the museum's elaborate surveillance system made no difference.

NEWS CLIP: Museum officials today said it was the largest art heist in history.

NEWS CLIP: Despite the confidence of museum officials that the precious artworks will be recovered, experts say they could disappear for years, perhaps forever. Brad Willis, TV4 Eyewitness News.

RODOLICO: The thieves who pulled off the greatest art heist in history had a pretty simple plan: They dressed up in cop uniforms and rang the bell. It was 1:24 in the morning and the thieves approached the Palace Road entrance of the Gardner Museum. There'd been a keg party nearby. A few revelers were still on the streets. And when the fake cops told the museum guard on duty that they were responding to a disturbance, it seemed plausible. Maybe some drunk kid had gotten up to some mischief. After all, earlier in the evening the guards' rounds had been interrupted by a fire alarm blaring from the museum's carriage house outside. It had really spooked him. Maybe that's why the cops had come and so he buzzed them into the museum.

HORAN: That guard was Rick Abath.

RICK ABATH: They came in and they turned, so I could see them. I could see that they had hats, coats, badges — they looked like cops, so I buzzed them the rest of the way into the museum.

HORAN: Steve Kurkjian and Rick Abath talked about that night at an Indian restaurant in 2013.

ABATH: The first question was, "Is anybody else here?" I said, "my partner." So, "OK, get him down here."

HORAN: We are devoting our entire second episode to Rick Abath. You'll be hearing a lot from him then. So, here, we're going to let you hear from the other guard who was on duty that night. The one that Abath called back to the security desk. This is the first time that former guard has ever spoken publicly about his experience.

RANDY: Wondering if they might just come up behind my head with a gun with a silencer and just you know do it real quickly.

HORAN: It was a terrifying night and, all these years later, he'd still rather we not use his full name. His first name, though, is Randy.

RODOLICO: In 1990, Randy had a passion for symphonic music, The Moody Blues and the trombone. He still plays — makes a living at it, mostly in house bands on cruise ships. But back then, Randy had recently earned a masters in performance from the New England Conservatory of Music. He was trying to land gigs and make ends meet.

RANDY: But I always had to have some kind of a day job kind of thing to supplement the income, make sure the bills get paid and so forth.

RODOLICO: Randy knew a couple of people who worked at the Gardner and that's how he landed his security job there.

RANDY: It wasn't something that required you to have any kind of special skills, you know. I remember being trained to if any people were getting real close to a painting, we were told to get them to stand back a little bit and don't get so close.

RODOLICO: A few months into his job, Randy began filling in on the overnight shift. The pay was better: $11 an hour versus 7 or 8 bucks for the daytime shift.

RANDY: At nighttime, when there are no visitors, when you're not doing a round, you can bring stuff to read. I could bring my horn and practice. I was always happy to say yes to filling in.

HORAN: Randy doesn't recall any special training or specific instructions for the night shift beyond the requirement that he register his presence in each of the galleries on all the floors during his rounds. He did this by swiping a magnetic strip. He wasn't originally on the schedule to work the overnight after St. Patrick's Day. Randy was filling in for another guard who had reportedly called in sick. Abath had told him about the carriage house alarm, but he hadn't thought much of it until he saw the two police officers talking to Abath at the watch desk.

RANDY: It never occurred to me that they might be anything but Boston police. I immediately made that connection. Oh, this might have something to do with that alarm that went off.

HORAN: One of the uniformed men said he recognized Abath and asked to see his ID.

RANDY: He said, “Yeah I do know you. There's a warrant out for your arrest.” And he told Rick to stand against the wall, put his arms up. He does the pat down. He puts the cuffs on. And I'm just standing there with my jaw open going, “Wow, you know, what's going on? What did Rick do? Is he really into some kind of trouble?” It's still never occurred to me that they were anything but policemen.

HORAN: By stepping out and away from the desk, Rick Abath also stepped away from the sole means of signaling trouble to the outside world: the museum's panic button.

RODOLICO: No sooner was Abath against the wall and handcuffed than Randy was too.

RANDY: I kept asking him over and over, “Why are we being arrested? Why are we being arrested?” and he wouldn't answer. So the cuffs are on, my hands are behind my back and then duct tape starts going on around my eyes. So about the time that he begins putting the duct tape on, he says, “This is a robbery.” And so then everything was finally crystal clear what was going on, you know. It was just really strange, none of it made any sense, and then suddenly it made a lot of sense.

HORAN: I mean it's scary enough to think you're being arrested and not know why. What was going through your mind when suddenly duct tape is going around your head?

RANDY: It's very scary and I'm worried for my life. But they were immediately saying — I can remember both of them saying — you know, “Follow instructions and you will not get hurt.” So that gave me some relief and I just felt like, “OK, don't try anything stupid, don't try anything stupid. Go along with whatever they — there's nothing here in this museum that is worth my life.”

HORAN: The thieves wound duct tape around Randy and Abath's heads from chin to scalp across their eyes and across their mouths with only a slit so they could breathe. Then, stair by stair, the robbers led the guards — who couldn't see a thing — down to the basement. One of the thieves used another pair of handcuffs to attach Randy to a drainpipe under a limestone sink near a boiler. Randy recalls that that thief was the calmer of the two and weirdly courteous.

RANDY: The guy who cuffed me, he was making sure that they weren't too tight on my wrist and he adjusted it several times and he said, “You're going to be here for a long time so I don't want these to be too tight.” So he was real calm and real nice about it and he also several times said, “Sorry to have to do this.”

RODOLICO: Randy just wanted the guy to get away from him, to go do what he had come to do and to get out of there.

HORAN: Were you panicking?

RANDY: It was scary and I remember feeling like I needed to prepare myself for death, if it ended up coming to that.

RODOLICO: What did that mean, preparing yourself for death?

RANDY: Well, I was running music through my head a lot, just feeling like I don't know what happens to us when we die. It's all a mystery. But, I just felt like I needed to be mentally prepared.

HORAN: Was there a particular piece of music that you ran through your mind?

RANDY: Definitely I remember one of the pieces: the Mozart “Requiem.” It didn't occur to me [until] later that that has to do with that has to do with dead people.

RODOLICO: Randy spent the next eight hours shackled on the basement floor, terrified the entire time that the thieves would return to kill him.

HORAN: Besides the thieves, no one knows more about what happened the night of the robbery than Anthony Amore does. He took the job as security director at the Gardner Museum 15 years after the heist. He is the beating heart of the investigation. Organized, meticulous, dogged — you might even say haunted.

AMORE: This case is like the perfect storm for someone like me — for it to like ruin your life. You know, to have 13 albatrosses around your neck forever because I know that if I go to my grave unsuccessful that I'll go to my grave an unhappy person.

HORAN: Amore has access to the FBI's files and says he talks to the Boston FBI's lead agent on the case every day. He has elaborate spreadsheets for cross-referencing details about potential suspects and he responds to every single tip. Even the patently cuckoo ones, 'cause you never know.

RODOLICO: The first thing Amore did when he took over the investigation of the heist was plot the thieves' movements throughout the museum. Every time a thief tripped a motion sensor, a dot matrix printer at the watch desk recorded it.

AMORE: And that's when the computer starts reading, indicating to a guard at the desk who's not there. It's telling him someone is in the Dutch Room, investigate immediately.

RODOLICO: He plotted every single alarm — there were hundreds — over a floor plan of the museum. The result is a minute-by-minute PowerPoint that shows the thieves moving through the museum.

AMORE: And if I didn't show this to you and I told you I would spend hours looking at this back and forth you would think that's crazy. But when you see it, that's as close as you'll ever get to witnessing the crime because that's precise, it’s exactly how they moved about the museum, so it’s eerie.

HORAN: It is eerie and it tells us that after cuffing and blindfolding the two security guards in the basement, the thieves made their way straight to the Dutch Room, in the southwest corner of the museum just off the stone step staircase on the second floor. The Dutch Room is named for its Dutch and Flemish treasures but the room is better known now as one of the scenes of the robbery.

AMORE: Keep in mind, it's three minutes until the heist. The vast majority of art heists I've ever looked at take about three minutes. Right, so it wouldn't surprise me if this theft was over in three minutes.

RODOLICO: But the Gardner heist wasn't over in three minutes. The thieves were in the museum for an astonishing 81 minutes. From the moment they were buzzed in at 1:24 until they left at 2:41.

HORAN: And their movements across galleries tell us they were stealing less than half the time — around 34 minutes.

AMORE: It's 34 minutes. My god, you could have wiped out galleries. Thirty-four minutes would be one of the longest art heists in history. I mean, one of the five longest art heists in history.

HORAN: So does that suggest to you amateurs?

AMORE: No, it suggests to me confident thieves.

HORAN: Confident thieves. Remember, they were quick to get Rick Abath away from the panic button. Anthony Amore says the thieves had the run of the place and they knew it.

AMORE: These were not scared pranksters, right, who are running around with nervous energy. You only have to look at the Rembrandt self-portrait etching to know not only weren't they hurrying, they were calm, because you could just have taken it — the frame is smaller than an 8-by-10 piece of paper — but they stood there and unscrewed the thing, methodically, there's a lot of screws in the back of that frame.

RODOLICO: The thieves lay the Rembrandt etching on a table face down and removed each screw one by one and while they did that, they left behind works of far greater value.

AMORE: The thief is standing beneath a Rubens painting, taking an etching, like I would like to have that etching but this is a Rubens masterwork. If you looked up, he'd see a Van Dyke portrait. Nope, just cavalierly unscrewed this little etching, like he had all the time in the world.

HORAN: And you think, though, that he just, he wanted a Rembrandt?

AMORE: They definitely, in my mind, came for the Rembrandts. I think this bears it out — they went straight into that room and went right for Rembrandts. They took all four Rembrandts off the wall. It's not a mistake that they went to the Dutch Room.

HORAN: And why Rembrandt?

AMORE: Well he's per capita, per piece of work in his body of work, he's the most often stolen artist.

HORAN: Besides the three Rembrandts in the Dutch Room that the thieves stole, they also took Vermeer's “The Concert,” a landscape by Govaert Flinck and that Shang dynasty gu. Does that to seem like a random grab to you? What's the significance of the gu?

AMORE: It does seem like a random grab, and it's always been a mystery to me. Why did they take that? And for years I just assumed that it was an afterthought. It was just there, grab it; or maybe they knocked it over and picked it up and just took it; a gift for your grandmother or something because it looks like a vase. But then I came across something really unusual that told me this was not a random piece. Do you want to see it? You should feel how heavy this is.

HORAN: What Anthony Amore showed me in his office that day totally changed how I thought about the theft of that piece. He pulled out a sheet of metal that's about a foot square and just as he said, it was really heavy. The gu sat on a silk draped table in the Dutch Room and it was anchored to that heavy metal through the tablecloth.

AMORE: So if you play it out, the gu is sitting there, the thief tries to take it, it doesn't come.

HORAN: And so you figure they thought that just by cutting the fabric they'd free the gu but then --

AMORE: Cut, cut, cut still doesn't come and then finally using force, they pull it off here. That's a lot of effort.

HORAN: Yeah. OK, so the gu was not a random grab. Wow.

AMORE: It's not a random piece.

HORAN: Someone wanted that gu.

RODOLICO: We know from Anthony Amore's PowerPoint that the thieves, along with 13 irreplaceable artworks, were last seen at 2:41 a.m. leaving the museum through the same door they came in — the one to Palace Road. But the guards in the basement didn't know that.

RANDY: So I'm sitting there and it's all quiet, and then suddenly I just hear a voice go, “Listen up,” like that and it made me jump because I didn't hear the footsteps coming up to me.

RODOLICO: Randy says a thief had checked on him at least once during the robbery. He told Randy, “Don't tell him nothing. If you're good, expect a reward in a year.” And he also told Randy something else.

RANDY: He said, “We know where you live. We have your driver's license. We know where you live.”

RODOLICO: So, startled by the thief's sudden presence and feeling the weight of that threat, Randy says when he heard voices coming from the direction of the guard desk many hours later he didn't dare make a sound.

RANDY: I was afraid to call out because I thought it was still thieves and then they — if they hear me calling out — they might decide, “This guy's being unruly, let’s just kill him,” or I don't know, I didn't want to take that chance.

HORAN: Around the time the security guards Randy and Rick Abath were found by police, Anne Hawley got a call at home. She was barely six months into her job as director of the Gardner Museum.

HAWLEY: So I just dropped everything and went into the museum in my blue jeans and when I got there, I was in shock.

HORAN: It was every museum director's worst nightmare. Hawley had needed persuading to take the job in the first place, but once in the role she set about trying to reanimate a museum she felt was stopped in time. Now, she was facing the unimaginable.

HAWLEY: It was overwhelming to see what had been done. I mean to trash a museum like that. It was just like the barbarians had been through. I mean, to pull frames off the wall and shatter the glass, it was clearly not people that loved art that did that. I mean, cutting paintings out of frames. I mean, it's unspeakable. And I guess I experienced this, I often think of it's like having a death in the family. It's just, it's too big to really talk about.

HORAN: Hawley describes the magnitude of the loss this way.

HAWLEY: Well, I always say for people who find it hard to imagine the enormity of this, who maybe are musically-oriented or theatrically-oriented to imagine what if Beethoven's Fifth Symphony could never be heard again, or what if Louis Armstrong's work could never be heard again, or what if Hamlet could never be played again. I mean, these are works of a civilization that are so important — to remove them is to remove a piece of our civilization.

HORAN: The lost piece of our civilization that cut Hawley the deepest, the stolen painting that most haunts her, is "The Concert" by Vermeer. Hawley, who had trained to be a singer, says Vermeer captures an ephemeral moment just right.

HAWLEY: “The Concert” is one of his really great paintings and it depicts three people — a man and two women making music together. And its beautiful composition of a woman sitting at a harpsichord playing and a lute player with his back to you who has a very mythical appearance and then a woman standing at the harpsichord. So you have this triangulation of the musicians and she's about to break into song and it's just such a meditative, quiet, beautifully painted picture by Vermeer and having that in Boston was one of Boston's treasures.

HORAN: Today, "The Concert" alone is valued at upwards of $200 million, making it the most valuable piece stolen from the Gardner. When Isabella Stewart Gardner bought the painting at auction in Paris in 1892 she outbid the Louvre Museum to do so. It was her first major triumph as a private collector. But the painting that Gardner considered the cornerstone of her entire collection — a large Rembrandt self-portrait — that was initially thought to be missing, too.

HAWLEY: And the frame was leaning against a chest and it had been said it was gone, that they had taken it, but when I pulled the frame back it was still in it and I just, I mean, that was the only relief, the only moment of any grace in that room.

RODOLICO: So in all the thieves took six pieces from the Dutch Room: five of them Dutch paintings and that Chinese gu and we know that they took six more pieces from the Short Gallery.

HORAN: That's the narrow slip of a room diagonally opposite the Dutch Room on the second floor. This room has the feel of a passageway, a room you walk through to get to other galleries.

RODOLICO: But the thieves stopped there and took the bronze eagle finial and five Degas sketches, which makes 12 pieces in all.

HORAN: But 13 pieces were stolen. That 13th piece is “Chez Tortoni” by Manet. It was in a first floor gallery, the Blue Room.

AMORE: There's no alarm in the Blue Room, on the first floor. All of the motion sensors from that night were either the doors when they came in or out or the second floor.

HORAN: So what does that tell you?

AMORE: As someone who looks at these art heists, constantly, I can tell you there it looks like two different crimes. Something's not right. There's no getting around that if something is not right. When you look at what was taken from the second floor, the manner in which was taken, and what was taken from the Blue Room on the first floor, it's almost as if it were two different heists because the M.O. is different. They're not similar except that they happened the same night.

HORAN: Is it possible the thieves didn't steal “Chez Tortoni” from the Blue Room? And if so, who did?

RODOLICO: Next time: Was the Gardner heist an inside job?

Last Seen is a production from WBUR and The Boston Globe. Digital content was produced in partnership with The ARTery, WBUR's arts and culture team. Read more on the Gardner heist from The ARTery.