BART's police chief asked for patience from the public on Sunday after video footage surfaced showing one of his officers fatally shooting an unarmed man who was on the ground on a station platform on New Year's Day, and after an attorney for the dead man's family said he planned to sue the transit agency for $25 million.

Chief Gary Gee said he, too, had seen video images of the shooting of Oscar Grant, a 22-year-old supermarket worker from Hayward. But Gee said he found the footage to be inconclusive, and he said his investigators still needed to interview a key witness - the officer himself.

That officer, a two-year veteran, has not been publicly identified and has been placed on routine administrative leave. BART officials have said only that his handgun discharged at about 2:15 a.m. Thursday at the Fruitvale Station in Oakland and that the bullet struck the unarmed Grant, who had been detained with several others.

Officials have not said whether the officer intended to shoot Grant. One source familiar with the investigation said BART is looking into a number of issues, including whether the officer had meant to fire his Taser stun gun rather than his gun. Alameda County prosecutors are conducting their own investigation, as is standard in officer-involved shootings.

I wouldn't be surprised if he did. The police use their stun guns on people who are already on the ground and offering no threat all the time. It's no wonder that one of them would get confused and just start shooting people in the same position. They have no sense of what constitutes a real threat anymore.