RIVERSIDE, Calif. -- The Riverside police officer killed Sunday night may have been shot with his own gun after he chased down the driver of a stolen big rig and fought with him in a city park, authorities said Tuesday.
Witnesses told detectives they saw the officer and driver in an altercation in Fairmount Park seconds before shots were fired. The man fled the scene in the semi-truck, escaping about a minute before other officers arrived to find Officer Ryan P. Bonaminio lying mortally wounded on the grass.
Bonaminio's gun was not recovered, and investigators said it was unclear if he fired his weapon. Detective Ron Sanfilippo said it's "very possible" that the suspect was able to get Bonaminio's gun and shot him with it.
"We're looking into that," he said, "but we don't know for sure."
Late Tuesday, police arrested a potential suspect in the officer's slaying at a Target store in Riverside. A store employee said at least a dozen heavily armed officers swarmed the parking lot about 8:20 p.m. but said little else under orders by the store manager.
"We like this guy, but there's still a lot of work to do," Riverside Police Chief Sergio Diaz told the Riverside Press-Enterprise in the store parking lot.
An emotionally spent Joseph Bonaminio, the officer's father, earlier urged the suspect to turn himself in to "let justice do its job." He said his son, a 27-year-old Army veteran who returned from his second tour in Iraq just a year ago, deserved nothing less.
"He's been home one year. He gave his life on our soil, and we want to know why," Joseph Bonaminio said, standing before the media with his wife and daughter. "I just wish this person would just come forward. Those people out there, if you know this individual, make him come forward.... Let's put an end to this. I'm just looking for justice, that's all."
Diaz announced that $390,000 in reward money had been raised for information leading to the arrest and conviction of the suspect. On Monday investigators released a photograph of the suspect, and on Tuesday they released a seven-second video of the man jumping into the big rig and fleeing, images captured by the camera in Bonaminio's squad car.
"We think that people who know this person have recognized him from the photo already. We think this almost $400,000 in reward money that's been offered will loosen some tongues. It's a lot of money to forgo for protecting a criminal like this," Diaz said.
The chief expressed "every confidence" that the officer's killer would be captured swiftly and said the FBI and multiple state and local law enforcement agencies were assisting with the investigation.
Detectives believe the man is a "graduate of the state prison system who knows how to operate a truck," which will greatly narrow the pool of suspects, Diaz said.
Bonaminio, who had been with the Police Department since 2006, was on routine patrol about 9:40 p.m. Sunday when he tried to pull over a stolen semi-truck believed to have been involved in a hit-and-run collision near the 60 Freeway.
The driver of the trailerless cab sped south on Market Street before pulling over in front of Fairmount Park and running into a field. Bonaminio called in his location to the police dispatch center and ran after the driver.
Sanfilippo said witnesses in the park, affiliated with a local church, saw the deadly encounter and have "assisted us." He declined to provide more detail, saying it could impede the investigation.
The truck had been stolen from a rental lot just outside city limits; the man returned the rig to the same lot after the shooting. Sanfilippo said analysts are processing the vehicle for fingerprints and other possible evidence.
While the incident will be reviewed thoroughly, the police chief said that Bonaminio appeared to have followed proper procedure in trying to apprehend the suspect, and that there was no evidence he knew the man had a gun.
In cases in which suspects are believed to be armed, officers are instructed to wait for backup, Diaz said.
"I certainly don't blame Officer Bonaminio for any of the decisions he made on that fateful night, and there's nothing that jumps out at me as a mistake made," Diaz said.
"Officers put themselves in the face of danger, in the way of danger, all the time.... That's police work. That's what we do," he said.
Police described the suspect as a black male in his mid-30s to mid-40s, about 6 feet 1 or 6 feet 2, with a slender build and possible facial hair.
He was last seen wearing dark clothing and a light-colored baseball cap. Authorities have received a number of tips about possible suspects, but thus far none has emerged as a person of interest, Sanfilippo said.
On Tuesday, the Riverside County Board of Supervisors, Riverside City Council and Riverside County district attorney's office each approved $100,000 in reward money.
The U.S. Marshals Service, FBI and Bureau of Alcohol, Tobacco, Firearms and Explosives combined to add $55,000; the Riverside Police Officers Association contributed $25,000; and the Morongo Band of Mission Indians contributed $10,000 to the reward fund and $10,000 to a family memorial fund.
Supervisor John Tavaglione, whose son served with Bonaminio on the police force, said the board authorized the reward to ensure there was "quick justice to bring this despicable coward who took Ryan's life ... to justice and put him away -- not for life, but to death. And I hope that happens very quickly."
Bonaminio was a Riverside native who joined the Army after graduating from Ramona High School in 2000. He served two tours in Iraq as a military police officer.
Army Spc. Brian J. Roy remembers serving in Mosul, Iraq, with Bonaminio in 2008-09.
"I always had to hand it to him; he always looked after us," Roy wrote in an e-mail. "He was a great mentor to all of us. He was always easy to talk to whenever we had problems.... Sgt. Bonaminio was a great friend and a great brother to us all."
Times staff writers Tony Perry and Kimi Yoshino contributed to this report.
Visit the Los Angeles Times on the Internet at http://www.latimes.com/.
Distributed by McClatchy-Tribune Information Services.