Metro officials cut short an investigation into the death of a man found on the tracks at Farragut North two years ago, and withheld video evidence about his death from his family, said a former Metro police detective.

James Duncan, who worked for the agency for 25 years, challenged Metro's handling of the death on the tracks of rider Lou Stancari in a whistleblower complaint filed with a federal agency.

Stancari's dismembered body was found at Farragut North in the late morning of Jan. 15, 2011. Metro said he swiped his SmarTrip card at Dupont Circle just before the train system closed the night before.

A medical examiner ruled that Stancari, 63, a set designer and Smithsonian archivist, died of multiple blunt impact injuries, and Metro said he was hit by a train. The transit agency ruled the death an accident and closed the case about a year later, saying it had exhausted all leads.

But Duncan said in a complaint filed with the Occupational Safety and Health Administration that Metro told him to stop investigating, despite his belief that the death could have been a homicide. He also said Metro officials showed an incorrect or doctored video of the night's events to Stancari's family and friends in an effort to dissuade them from suing the agency for negligence.

Duncan said while he was investigating the death, he saw a surveillance video that showed Stancari and another person leaving a train at Farragut North. Moments later, the film showed the other person "acting erratically and then appear[ing] to run off."

When Stancari's family and friends asked to see videos of the Dupont Circle and Farragut North stations, Metro officials showed them tapes with vague images, Stancari's sister, Emily Schalk, and friend Bruce McKaig said.

Stancari's friends said they believe Metro bungled the investigation.

"There's so many steps along the way of people screwing up. And how could you say it was an accident?" said Cathy Notarnicola, Stancari's friend and neighbor. "They just didn't do their jobs."

Metro said it showed the family the video that included a "person of interest" that police were looking for, though Metro said it did not suspect that person of being involved in Stancari's death. The agency denied that any video existed in which Stancari could be identified leaving the train.

Duncan left Metro after he said the agency retaliated against him when he tried to raise the Stancari case and other matters with the agency's inspector general. Metro declined to comment on why Duncan no longer works for the agency.

Stancari's sister said Duncan had persuaded her that Metro may have given the family an incorrect or doctored video because employees were negligent and did not do required checks before closing and opening the station.

"There's just all these little lies from the very beginning," Schalk said. "We were not shown that video. I mean, who knows what they showed us just to keep us quiet?"

Metro usually hands off murder investigations to D.C. police, but Duncan's supervisors refused to do so despite his suspicions that it was a homicide, he said. Metro said the case was not forwarded to police because there was no evidence of foul play.