Opening statements were made Friday in Ventura County Superior Court in the trial of a former Oxnard police officer accused of barricading himself in his Ventura home last year, imprisoning and assaulting his then-live-in girlfriend.

Afterward, the prosecution called its first witness, a 10-year-old boy who testified about an unrelated incident involving the defendant.

The witness, whose name is being withheld by The Star because he is a minor, testified about a 911 phone call he made in April. The boy said he made the call because he was told to do so by his mother, who is currently dating the defendant, Robert Perez Jr.

The boy said he had been asleep and when he woke up he heard "a banging on the table" as his mother and Perez argued.

He added that he later heard Perez say, "If you push me or shove me, I'll hurt you real bad."

The boy's testimony is being given because, prosecutors say, Perez has a propensity for violence.

He is charged with assault with a firearm, false imprisonment by violence, three counts of dissuading a witness from reporting a crime, battery and resisting arrest.

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 lived with his then-girlfriend, Denise Shadinger, and used a firearm to keep her from leaving, according to prosecutors. She is an Oxnard police officer, prosecutors said.

Accusations listed

Perez is accused of barricading himself in the residence with a handgun and an assault rifle after Ventura police responded to a report of a domestic dispute at the home more than four hours earlier.

During opening statements, prosecutor Andrea Tischler described Perez as someone who always needs to be in control of everything, and "this extends to the women he dates" and "the situations that he is placed in."

Perez's lawyer, Mark Pachowicz, urged jurors to wait to hear all the evidence and testimony before drawing any conclusions. He said Shadinger gave statements that weren't truthful and exaggerated what was going on, which, he said, resulted in the escalation of an incident where the SWAT team responded to the 911 call.

"Just because Miss Shadinger says it doesn't mean that it's true," said Pachowicz, adding that she told "half the story" to police.

Tischler told jurors that Perez and Shadinger owned a home together and said the July 29 incident was the second time she was assaulted by Perez. Tischler said the first time was on May 1, when Perez found a note at work and believed that Shadinger might be having an affair.

Tischler said Perez confronted Shadinger, and an argument ensued, followed by Perez punching and kicking Shadinger. She didn't report that incident but told friends of the assault, the prosecutor said.

Photographs of the alleged May 1 injuries were shown to jurors, who also heard the 911 calls of the July 29 situation to the dispatcher.

At one point in the tape, a voice identified as Shadinger's is heard saying to the dispatcher in a calm voice, "We are all right. We're fine."

Actions in house described

Tischler told jurors that Perez held Shadinger, who suffered very minor injuries, against her will for several hours. Shadinger at one point was cowering inside a closet, and Perez pointed a gun six to 12 inches from her head, the prosecutor said.

Perez also shattered a telephone, took away Shadinger's car keys and twice kept her from completing calls to 911, said Tischler, who added that Shadinger was allowed to leave at 2:30 p.m.

While the SWAT team surrounded the house, Perez drank seven beers and refused to come out of the house. Tischler said Perez heard what was going on outside through his police radio.

Tischler said Perez told police that he wanted to talk to his lawyer and a bail bondsman, and gave police instructions on how to arrest him. After he was arrested, Tischler said, Perez told officers that he could have "finished you up before when I had you in my sights."

Pachowicz told jurors there was a good reason his client didn't follow an officer's instructions as he was being arrested but didn't describe it.