Thomas Jason James Smith, 28 filed the federal lawsuit against Millvale Officer Nichole Murphy, Chief Derek Miller, and the borough, which is just northeast of Pittsburgh.
The FBI announced in February that it had launched a civil rights investigation when the video surfaced months after the incident on Sept. 21, 2012, when Smith was arrested for public drunkenness. It wasn't immediately clear if the FBI investigation was continuing, though no criminal charges have yet resulted from that probe.
FBI spokeswoman Kelly Kochamba declined to comment on the incident.
Smith's attorney, Gianni Floro, also declined comment on the nine-page lawsuit which offers few details beyond those publicly reported when the video surfaced in January.
The video shows a shirtless Smith sitting on the floor while he bangs his head on the edge of an office cubicle or desk before the officer shoots him with the stun gun. Smith isn't seen attacking the officer, though she had reported in a criminal complaint that she used the stun gun to subdue Smith when he became violent. The video also shows some unspecified emergency responders smiling and laughing at Smith's behavior.
Smith's criminal attorney, David Shrager, has said he doesn't know who recorded the video. Borough solicitor Jack Cambest, who declined comment when contacted by reporters Monday and did not immediately return a Tuesday call from the AP, previously said the video was taken by a police department employee, whom he wouldn't identify. Cambest said then that borough officials didn't know why the video was recorded or leaked.
Millvale conducted its own internal investigation to determine if police regulations were violated pertaining to the video, as well as how Smith was treated. Cambest previously said Officer Murphy was disciplined -- though he wouldn't say how -- and retrained for her use of the stun gun, but not suspended.
According to Smith's lawsuit, Murphy had been fired -- and then rehired -- by the borough before the Smith encounter because of unspecified "conduct similar to that which is the subject of this complaint."
The lawsuit contends Smith was walking home from a friend's house after drinking, and was arrested by Murphy when he stopped to rest on some church steps. Smith, who has a history of mental health issues, didn't resist arrest but did bang his head against a desk or office cubicle repeatedly after he was made to sit on the floor of the police station, still in handcuffs.
"At no time was he a danger to anyone besides himself," the lawsuit contends.
When one paramedic pulled Smith away from the desk, he again scooted toward it and resumed banging his head, which is when Murphy used the stun gun on him repeatedly, the lawsuit contends.
Smith later pleaded guilty to disorderly conduct and public drunkenness, but police dropped charges of aggravated harassment and resisting arrest.
The lawsuit seeks more than $75,000 in damages, a statutory threshold necessary for it to be filed in federal court.