OAKLAND, Kalifornia - January 12, 2009 - With the officer who shot and killed Oscar Grant III still refusing to speak to investigators, BART police completed their investigation into the New Year's Day shooting and handed the case over to the county prosecutor's office, officials said Monday.

"It is now the Alameda County District Attorney's responsibility to examine the evidence, complete his investigation and decide whether and which criminal charges should be filed," BART General Manager Dorothy Dugger said. She added that she had urged District Attorney Tom Orloff to fast track his own investigation and make his decision as quickly as possible.

Former officer Johannes Mehserle has appeared in several videos recorded by witness cell phones on New Year's Day firing his gun into Grant's back as Grant lays face down and restrained. Hundreds of protesters have rallied throughout the past two weeks, calling the shooting a murder and demanding Mehserle be arrested immediately.

BART police Chief Gary Gee said his department did not make a recommendation on whether charges should be filed against Mehserle.

Gee said that detectives interviewed six BART police officers that were on the Fruitvale station platform with Mehserle at the time of the shooting. He said they also interviewed 21 other people who witnessed the incident.

Gee said that Mehserle did have a stun gun at the time of the shooting - located on the opposite side of his belt from the firearm - and did not use it.

Orloff had said he would not decide until the end of next week whether to file charges against Mehserle, but after BART's announcement Monday, he said that time frame could change. The transit agency's submission of its police report "may help me speed it up," he said.