LAS VEGAS - O.J. Simpson wants a judge to bar any mention of the former football star's 1995 acquittal in the slayings of his former wife and her friend when he stands trial on kidnapping and armed robbery charges, his lawyer said Friday.

"We don't want the state to be able to bring that up at all,'' lawyer Gabriel Grasso said. "That's not part of this case.''

Grasso also filed court papers seeking the dismissal of half the 12 charges against Simpson, saying prosecutors in Nevada failed to meet legal standards to prosecute him.

"They're charging O.J. with ... the specific intent to commit robbery,'' Grasso said, citing Nevada law underlying the felony charge of robbery. "He wasn't stealing from somebody else. He was taking back something that was his.''

Simpson, 60, is accused of leading five other men in a gunpoint robbery of two memorabilia dealers who were peddling collectibles associated with Simpson, including the suit he wore the day he was acquitted in the murders of his ex-wife, Nicole Brown Simpson, and her friend Ron Goldman.

Simpson has denied any knowledge of guns being involved in the confrontation. He has said he intended only to retrieve items that had been stolen from him by a former agent.

"Simpson's indisputable sole intent to retrieve his own property negates the crime of robbery as charged,'' Grasso said in Thursday's court filing. He also contended that "the crime of kidnapping was not shown to exist to the slight or marginal extent required under Nevada law.''

Grasso said Simpson would fight the other six charges against him at his trial, set to begin April 7. Those counts include burglary, coercion and assault with a deadly weapon.

On Friday, Clark County District Attorney David Roger filed four motions, including a request to be able to tell jurors that Simpson was trying to tamper with a witness when he left a telephone message allegedly asking his former bail bondsman to pass a message to co-defendant Clarence (C.J.) Stewart. He declined comment pending a March 7 hearing.

"We're going to let the documents speak for themselves,'' said Dan Kulin, a spokesman for the district attorney's office.

District Judge Jackie Glass has set a Feb. 21 deadline for prosecutors to respond and a March 7 hearing on motions in the case.

Stewart and Charles Ehrlich are being tried with Simpson; three former co-defendants have pleaded guilty.

Stewart and Ehrlich have also challenged some of the charges and Ehrlich's lawyers have asked the judge to separate his trial from Simpson's.

Simpson, Stewart and Ehrlich are all free on bond after pleading not guilty to all charges.