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Trial Begins for Alleged Gang Member Accused of Murdering Pomona SWAT Officer

A reputed Mongols motorcycle gang member who shot and killed a Pomona SWAT officer was warned loudly and repeatedly that police were at the door, a prosecutor told jurors Monday, while a defense attorney countered that his client was convinced Mongols members had come to get him and fired to protect his family.

During their opening statements, both sides agreed that David Martinez, now 41, fired a bullet from a 12-gauge shotgun at 45-year-old Officer Shaun Diamond, who was part of a team of officers serving a warrant in the early morning hours of Oct. 28, 2014, at a San Gabriel home at 138 N. San Marino Ave. where Martinez lived with his parents, common-law wife, their 10-year-old son and baby, and his adult sister, who has Down syndrome.

Diamond was helping to open a metal screen over the front door of the home as part of a multi-agency operation targeting the Mongols gang when an interior door was opened and a single shotgun blast rang out, striking him in the neck. He died the next day.

 

The SWAT team members had begun prepping for the search two days earlier and were “concerned with the safety of everyone involved,” not just police, Deputy District Attorney Michael Blake told the seven-woman, five-man jury.

“(Their) uniforms are covered with patches and insignia that identify them as police,” and “they made announcements repeatedly” calling out “Pomona Police Department … open the door,” Blake said.

The team got to the house around 4 a.m. and were prepared for other family members to be there, the prosecutor said.

“The real danger to everyone involved came not from the police but from one Mongol biker gang member inside, David Martinez,” he said.

Martinez’ father, who slept in the living room with his wife and the couple’s daughter, opened the door. Martinez’ mother told police that the porch light was on and she “saw four or five police officers standing on her porch and then an explosion,” according to Blake.

The prosecutor showed jurors the shotgun and ammunition used.

“This is not ordinary shotgun ammunition … (but) a slug made from a solid piece of metal,” Blake said, telling jurors that its use “reveals a shocking and callous brutality.”

The shot severed Diamond’s spinal cord and completely destroyed the bottom half of his face, the prosecutor said.

“Throughout this awful incident … the Pomona SWAT team remained calm and professional,” still proceeding to search the house and detain family members, he said.

“They did not return fire. They did not shoot up the house … they did not use force on a single person,” Blake said.

When officers walked into the house, Martinez was turning away from the door and dropped the shotgun and said, “I’m sorry. I’m sorry. I thought you were Mongols,” Blake said.

“The evidence in this case will prove those statements were false,” he said, telling the jury the comments were “calculated.”

Two other guns, a .44-caliber revolver and a 9mm semi-automatic pistol, were found in the house, along with methamphetamine. Officers also found a leather Mongols biker vest and motorcycle license plate that the prosecutor said Martinez wouldn’t be allowed to possess unless he was still in good standing with the outlaw motorcycle club that refers to it members as “one-percenters.”

“These one-percenters respect no one outside their gang … submit to no authorities outside the gang,” Blake said.

There is “no credible justification or excuse for what this man did,” he said. “David Martinez left his house that day a murderer … he saw an opportunity and he took his shot.”

Defense attorney Brady Sullivan referred to the night of the shooting as a “perfect storm,” telling jurors, “Sometimes in life, a series of unexpected, unanticipated events combine, they come together and result in a tragedy.”

“When David Martinez came out of his bedroom and heard unknown people breaking into his house … he acted to defend his family,” the public defender told jurors. “He had no idea it was the police and, in fact, expected that it was going to be his rivals.”

Martinez had made a “regrettable decision to join the Mongols,” Sullivan said. “He was a motorcycle enthusiastic … he liked the brotherhood, he liked riding with a bunch of guys.”

He even got a tattoo of the group’s insignia — Genghis Khan on a motorcycle — on his chest, but later had regrets, his attorney said.

“David started to get tired of it. He didn’t like the Mongols’ lifestyle,” Sullivan said.

And after an accident in 2013, he never rode a motorcycle again, according to the defense attorney.

“He was afraid to quit (because) the scary truth is that you don’t just walk away from the Mongols,” he said. “They come and take your vest, they come and take your motorcycle and they exact a little physical punishment.”

Martinez was worried for himself and his family, particularly after freeway shootings between rival motorcycle gangs, and kept the shotgun by his bed and took two handguns out of a safe and kept them in his study, Sullivan said.

His client was in a bedroom at the back of the house and the noise from officers trying to open a large locked metal gate across the driveway, along with barking from the family’s three Chihuahuas and German shepherd, drowned out any announcements that they were police, according to Sullivan.

“They made so much noise that their commanding officer a block away heard metal on metal,” he told the jury. “The whole house (was) shaking.”

It was so loud that the team at the gate didn’t hear the gunshot that killed Diamond, according to the defense attorney. And Martinez couldn’t see the doorway once his father had partially opened the door, according to Sullivan.

“All he sees is his parents backing away,” Sullivan said. “He fired a warning shot.”

 

His father was also struck in the arm by the bullet that killed Diamond and yelled, “The police shot me.”

Martinez then saw Diamond fall off the porch and immediately surrendered, according to his attorney.

“I’m sorry. I’m sorry. I didn’t know it was the police. I thought you were the Mongols. I have problems with the Mongols,” he told police, according to Sullivan.

The public defender claimed that a detective anxious to convict Martinez falsified a report denying Martinez made those comments, and alleged it wasn’t the only report fabricated in the case.

“David reasonably believed when he looked out that door that they had come to get him … and he acted reasonably to defend his family,” Sullivan said, telling jurors that what happened was “tragic, sad, unfortunate, but accidental.”

During a preliminary hearing, sheriff’s officials said Martinez has a criminal history that includes assault with a deadly weapon and domestic violence.

Prosecutors decided against seeking the death penalty for Martinez, who could face life in prison without the possibility of parole if convicted as charged.

Diamond had 16 years of experience in law enforcement. He worked with the Los Angeles Police Department from 1995-2002, then with the Montebello Police Department from 2002-03. The married father of two joined the Pomona Police Department in 2006 and its SWAT team two years later.