Press "Enter" to skip to content

Jury unable to decide in trial of man accused of killing Pomona SWAT officer

The trial of a San Gabriel man accused in the 2014 fatal shooting of a Pomona SWAT officer ended in a hung jury on Friday, June 28.

After deliberating for nearly a week, jurors acquitted 41-year-old David Martinez of first degree murder but deadlocked on second degree murder with three voting guilty and nine voting not guilty.

Police Officer Shaun Diamond, 45, was shot on Oct. 28, 2014 while he helped serve a search warrant in the 100 block of San Marino Avenue in San Gabriel. He died the next day from his injuries.

Martinez testified at trial that he fired a “warning shot” at what he thought were fellow Mongols members trying to break into his family’s home.

Joy Diamond, who is the mother of the slain officer, declined to comment on the verdict. But volunteer victim’s advocate Tina Yamashiro said Joy Diamond was devastated.

“We are disappointed with the outcome,” Pomona Police Chief Michael Olivieri said, “but not disappointed at all with the professional work done by the Los Angeles County District Attorney’s office and the homicide detectives from the Los Angeles County Sheriff’s Department who have all worked tirelessly on this case.

“We are hopeful there will be a retrial,” he said.

The decision on whether to retry Martinez will be made at a later date, said Los Angeles County District Attorney’s spokesman Greg Risling.

It wasn’t clear if Deputy District Attorney Jacques Garden or Deputy Public Defender Brady Sullivan asked the jurors why they voted how they did. Garden declined comment while Sullivan could not be reached.

“Our office declines further comment,” Risling said.

Superior Court Judge Charlaine F. Olmedo ordered Martinez to return July 11 to the Clara Shortridge Foltz Criminal Justice Center in downtown Los Angeles for a hearing on motions in the case.

On the day Diamond was shot, a multi-agency operation targeting the Mongols motorcycle club was serving seven warrants. The Pomona SWAT, which was not part of the task force, was asked to serve the warrant at Martinez’s home.

The prosecution said police announced their presence and stated they had a search warrant. Diamond and Sgt. Richard Aguiar were assigned to breach the screen door and they did, using two tools.

Diamond, who was holding one of the tools, had his back turned to the doorway when Martinez’s father, Arturo, opened the front door. Martinez fired a 12-gauge shotgun, hitting his father in the arm and Diamond in the back of the neck. The slug severed Diamond’s spine and damaged his jaw and tongue.

“The defendant shot Officer Shaun Diamond while his back was to the defendant, while Officer Diamond’s gun was in his holster, while Officer Diamond was walking away from the defendant, ” Garden said during closing arguments.

“Officer Diamond posed no threat to the defendant. Zero threat.”

After the shooting, Martinez apologized to the officers who entered the house and said he thought it was fellow Mongols members at the door.

“I kept saying I was sorry,” Martinez testified at trial. “I didn’t know it was the police. I thought it was the Mongols. I would never fire at police or law enforcement ever. I have family that’s (in) law enforcement.”

Sullivan argued that the shooting was self defense. Martinez saw what he thought was the barrel of a rifle pointed at his father and fired a shot to protect him, Sullivan said.

“David acted to defend his family,” Sullivan said. .

He said Martinez, who was in a back bedroom, did not hear the police announcements but heard the loud banging made by other officers trying to force open a gate. He added that the family dogs were also barking.

Martinez wanted out of the Mongols, was at odds with some members, heard about the freeway shootings involving Mongols and had interpreted a text he received as a threat, according to Sullivan.

The prosecution doubted Martinez’s statement that he did not see Diamond. Garden pointed out that there was a light on the porch and that the officer stood 6 feet 2 inches tall and wore a green uniform with the word “police” on the back.

“Are we going to give the defendant a pass? Is this his free murder?” Garden asked. “How do you not see Officer Diamond with the light on?”

The prosecution also argued that Martinez was a liar who changed his story depending on his audience.

At the Montebello jail, Martinez told a fellow Mongols member he shot an officer in the face because the officer blasted his father, Garden said.

Martinez then said he didn’t fire the shotgun during a Nov. 7, 2014 phone call to his mother and another relative, according to the prosecution. In 2015, Martinez told a friend that his public defender wanted to call the shooting self-defense, the prosecutor said.

Garden said Martinez lied about fearing the Mongols and said the San Gabriel man remains a member of the group. He said the Mongols’ national president and other members deposited money in Martinez’s inmate account in county jail. Garden also played phone calls between Martinez and Mongols members that occurred while Martinez was in county jail.

City News Service contributed to this report.