25 years ago, $500 million worth of paintings, including works from Degas, Vermeer, and Rembrandt, were stolen from Boston's Isabella Stewart Gardner Museum in the largest art heist in American history. To this day, investigators are still looking into the crime and new video evidence might incriminate Richard Abath, who was thought to be a victim in the heist, the New York Times reports.

Abath was moonlighting as a security guard at the museum when he buzzed in the two men, disguised as cops, who would go on to steal the art. Abath was found with his hands bound and face covered with duct tape the morning after the heist. However, it's security footage from the day before the crime that is drawing attention now. 

In the footage, Abath is seen admitting a man wearing a coat with a popped collar into the museum through the same doors the thieves entered on the morning of the crime. The unidentified man drives his car to the side entrance, meets with Abath, and shows him a document before they step out of view from the security cameras. 

While FBI investigators have been careful to not directly accuse Abath, they did mention that while he has always cooperated fully with the investigation, he has never spoken about this instance. A red flag considering that letting the man in would have been against the museum's policy, according to the NYT. Also troubling is the fact that both visits occurred immediately after the second guard on duty left his post to do his rounds.

The video is being released now because the FBI is hoping the public will be able to identify the man and the make and model of the car he was driving.  

At the time of the heist, Abath was a 23-year-old self-proclaimed hippie in a rock band. Investigators have monitored his bank accounts since the heist and he has even passed two lie detector tests. He gave his two weeks' notice at the museum just before the crime took place. 

The New York Times was able to contact Abath's wife by phone. "I can’t deal with this right now," she told the publication before hanging up. 

Abath the morning of the crime / Image via the New York Times