An attorney for the family of a man who died while being held down by Minneapolis police is battling the city over an officer's tiny personal pen camera that shot video of the man's death and the home computer onto which the officer downloaded it.

Lawyer Robert Bennett has accused officer Timothy Callahan of withholding the video for six days before turning it over to police. Bennett said it might have been edited.

Lawyers for the city called Bennett's claims "baseless and offensive," saying the video was never edited and is consistent with a video taken by a Taser that police used in the incident and a video captured by an independent security camera.

Bennett has sued the city over the death of David Smith, 29, at the downtown YMCA on Sept. 9, 2009.

Callahan and officer Timothy Gorman were called to the YMCA by staff who complained that Smith, who was mentally ill, was being disruptive and acting bizarrely.

The video, shot by a pen camera that Callahan owned and had clipped to his shirt pocket, shows him and Gorman Tasering Smith, causing Smith to collapse to the floor, where the two officers held him face down for over four minutes. He stopped breathing, and although emergency workers revived him, he had no brain activity and was later declared dead.

The Hennepin County medical examiner concluded Smith died of cardiopulmonary arrest due to asphyxia, caused by the officers kneeling on his back and buttocks so he could not turn over or breathe. It was ruled a homicide.

Bennett told U.S. Magistrate Judge Arthur Boylan on Friday that he wanted the camera and computer examined by forensic experts he hired to see if the video was edited. Boylan took the matter under advisement.

Bennett said the computer also might contain other useful evidence such as e-mails. He said the camera might have recorded other confrontations involving the officer.

Tracey Fussy, an assistant city attorney, urged Boylan to reject Bennett's request, saying the city's forensic expert concluded there was no evidence the video was edited and that Callahan didn't have the expertise to do it. She said Bennett did not need the camera or the computer and that e-mails on the computer would be irrelevant.

Fussy also said it didn't matter whether Callahan gave the video to investigators right away. She said he consulted with Sgt. Jeff Jindra of the Minneapolis Police Federation, who advised him to first contact his attorney. Callahan gave it to the department when investigators formally interviewed him.

Boylan asked pointed questions of Bennett and Fussy, showing some skepticism with portions of both sides' arguments. He noted that Bennett lacked evidence that the video was edited.

Boylan also suggested to Fussy that Callahan might have used the computer to write about the case in e-mails Bennett might find useful.

Bennett told the judge that neither Callahan nor Gorman informed any supervisors, homicide investigators or fellow officers at the scene about the pen camera or video. He said Callahan claimed he forgot to disclose it, but the video shows him speaking to a sergeant while turning the camera off.

Callahan took the camera home, downloaded the video and watched it with his wife. He gave a flash drive with a copy of the video to police.

In court documents, Fussy said the city examined the officers' work e-mails and turned over appropriate documents to Bennett. Seeking the officer's personal e-mails "is an egregious personal privacy violation," Fussy wrote.

In a court document, Bennett said police didn't conduct a "real investigation," even though the two officers violated department policy by holding Smith prone without checking to see if he was breathing.

It includes an excerpt from a deposition by Capt. Amelia Huffman, who served "in a supervisory capacity over this case." Huffman was asked if officers had an obligation under the Fourth Amendment to continue to monitor a suspect's breathing after his arrest.

"Yes," she answered.

"That didn't happen in this case?" "No," Huffman answered. "There was a significant gap of time in which that did not happen."

The case is expected to go to trial next year.