Denise Shadinger, an Oxnard police officer, testified in Ventura County Superior Court on Monday about the troubled relationship with her former live-in boyfriend, a former Oxnard police officer who is accused of barricading himself at the couple's Ventura home after assaulting her last year.

Shadinger said she had been in a romantic relationship with Robert Perez Jr., whose nickname is JR, for more than 10 years and they lived together for seven years. She said she decided she was going to end the relationship after finding out that "JR was having numerous affairs."

Shadinger said Perez confronted her on May 1, 2007, when he found a typed note at work from an anonymous source that said she was allegedly having an affair.

Shadinger is scheduled to continue her testimony today in the trial of Perez, who 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.

Shadinger alleged that Perez assaulted her on two occasions in May and July of last year, but he is on trial solely for what happened on July 29.

On that date, Perez allegedly kept Shadinger from leaving their home and put a gun to her head. Perez surrendered to Ventura police about 7:20 p.m. outside the home in the 10000 block of Candytuft Street.

Shadinger said Perez punched and kicked her on May 1 at the couple's home after coming home with the typewritten note inside a manila folder.

She said she never reported the incident to police.

"Why didn't you report this incident to police?" asked prosecutor Andrea Tischler.

"I am not sure," Shadinger replied, adding that she told three friends about it. She said Perez told her that his career would be over if she reported the incident.

On July 29, Perez got upset and they argued because Shadinger decided she wasn't going to have sex with him, she said. They had planned to ride motorcycles with a group of other riders, but Shadinger said she got upset and refused to go riding.

The arguing escalated and Shadinger told Perez she was moving out, and he became upset, she testified.

What followed was more arguing and yelling, and at one point Perez refused to let her leave, she said, describing what went on for several hours. Perez was so upset with her for calling 911 that he stood over her and pointed a gun to her head, she testified.

"I had never seen him look at me that way," Shadinger said.

"Were you scared?" Tischler asked.

"Yes, I was."

The calls to the 911 dispatcher were played in court, including one in which Shadinger told police that Perez had a gun and was threatening to shoot officers.

Under rigorous cross-examination by Perez's lawyer, Mark Pachowicz, Shadinger admitted that she had several opportunities to leave the house and get help, including at one point being outside on the driveway by herself.

However, she said she didn't have shoes, keys, money or any identification. And she said she was upset.

"I did not know why I walked back in the house," she testified.

She admitted that she couldn't say for sure how the three minor injuries she said she received that day occurred.