Jury selection began Tuesday afternoon in the trial of a former Oxnard police officer who allegedly armed and barricaded himself in his Ventura home for about five hours last year.

Police have said that Robert Perez used a firearm to keep his then-girlfriend, Denise Shadinger, also an Oxnard police officer, from leaving.

The charges against him include assault with a firearm, false imprisonment by violence, three counts of dissuading a witness from reporting a crime, battery, resisting arrest and domestic violence.

The process of selecting a jury began after Ventura County Superior Court Judge Alan Steele made decisions on the evidence he will allow both sides to submit during the trial, which is expected to last until Aug. 8.

Perez, who is out on bail, was in court with his attorney, Mark Pachowicz, who questioned some of the evidence the prosecution plans to introduce.

Perez surrendered to Ventura police about 7:20 p.m. on July 29, 2007, outside a home in the 10000 block of Candytuft Street.

He is accused of barricading himself in the residence with a firearm after Ventura police responded to a report of a domestic dispute at the home more than five hours earlier.

Prosecutor Andrea Tischler told the judge that she planned to introduce evidence of other actions allegedly committed by Perez after he was out on bail, in order to show his "propensity for violence."

She said she'll also call a child witness, the son of a woman Perez is currently dating.

Tischler said the child once called 911 to say that Perez was "hurting" his mother, who is a Ventura County sheriff's deputy.

Tischler said the child also will testify that Perez "grabbed his mom's hand and wouldn't let her go because he was angry with her" during another alleged incident at a park.

Pachowicz told the judge, who ruled the evidence admissible, that "the only reason they want it in is they want to dirty up my client."

Pachowicz said if prosecutors "go down that road" he will subpoena Special Assistant District Attorney Michael Schwartz to testify about a letter he wrote to the female deputy.

The judge, however, said he found it hard to believe that the district attorney will submit evidence that Perez violated a restraining order by going to a wedding with Shadinger.

He said he also didn't understand why Tischler wants to admit evidence that Perez and Shadinger were text-messaging each other "back and forth" in violation of the restraining order.

Tischler later told the judge that she decided not to bring up the restraining order.

The judge described it as a "serious case" that prosecutors risk making it into "nothing" by bringing up such things as the wedding and text messages.

"I don't think the wedding should come in at all," said Steele, adding that unless the text messages are full of "ugly stuff," they should be left out, too.