A lawyer representing the white former San Francisco Bay Area rapid transit officer convicted of fatally shooting an unarmed black passenger is asking a Los Angeles judge to grant a new trial.

Defense attorney Michael Rains said in a 134-page filing Friday that Johannes Mehserle's involuntary manslaughter conviction should be overturned because jurors did not hear a similar case from Kentucky. In that April 2008 case, a police lieutenant mistook his handgun for a stun gun and shot a man in the back, wounding him.

The lieutenant was not criminally charged.

Rains also said Los Angeles County Superior Court Judge Robert Perry erred in his instructions to the jury and that Mehserle's gun enhancement conviction also should be overturned.

"We want a new trial on the involuntary manslaughter conviction," Rains said Monday. "And if the judge doesn't want to do that, then he should throw out the gun enhancement."

John Burris, attorney for the California victim's family, said Monday Rains' arguments have already been made in court.

"This is a rehashing of many of the old arguments made during the course of the trial," Burris said. "In our view, involuntary manslaughter is the lowest form of conviction because the evidence supported a higher conviction. In my view, the judge should raise the punishment."

A jury convicted Mehserle in July in the 2009 New Year's Day shooting death of Oscar Grant on an Oakland train platform. The incident was video-recorded by several passengers, shown on the Internet and subsequently used as evidence during Mehserle's three-week trial.

Mehserle said he feared Grant had a weapon and decided to shock him with his stun gun, but instead pulled his .40-caliber handgun. Grant was unarmed.

The incident let to protests and rioting shortly after the shooting and the July 8 verdict.

Mehserle's trial was moved to Los Angeles after a judge cited racial tensions and concerns about whether an impartial jury could be found in Alameda County.

The arguments for a retrial will be heard at Mehserle's sentencing, scheduled for Nov. 5 in Los Angeles. Mehserle faces a possible sentence of 14 years in prison.