SAN FRANCISCO — The lawyer for the former Bay Area transit officer accused of fatally shooting an unarmed man is asking a judge to lift a temporary gag order in the murder case.

Michael Rains, who represents former Bay Area Rapid Transit officer Johannes Mehserle, says the gag order has limited Mehserle’s efforts to “set the record straight” and could prejudice potential jurors in the case against his client, according to court documents Rains filed last Friday in Alameda County Superior Court in Oakland.

“The defense believes that the (gag) order has hamstrung Mehserle by preventing any attempt he might otherwise make to address the barrage of negative publicity in the case, which has presumed his guilt as a murderer,” Rains said in the filing.

Mehserle has pleaded not guilty to murder in the New Year’s Day shooting of Oscar Grant on a train platform in Oakland. Prosecutors say Mehserle, 27, shot Grant, 22, in the back while he lay facedown on the ground.

Mehserle is a 2000 graduate of New Technology High School in Napa and a 2006 graduate of the Napa Valley College Police Academy.

Rains argued at a Jan. 30 hearing that Mehserle, who was released last Friday on   $3 million bail, may have mistakenly pulled his pistol instead of a stun gun.

In Friday’s court filing, Rains says the attorney for Grant’s family, John Burris, who is not covered by the gag order, has been free to make allegations against his client that the defense cannot counter.

Rains says Burris has “offered a number of inaccurate and typically inflammatory statements.”

Burris said Monday he’s not involved in the criminal case.

“My job is to protect my clients’ interests,” he said.