Flyers were posted around the Sunset District reporting 41-year-old Catono Perez missing before his body was found in his apartment on Great Highway. (Corey Browning/Special to the S.F. Examiner)

Flyers were posted around the Sunset District reporting 41-year-old Catono Perez missing before his body was found in his apartment on Great Highway. (Corey Browning/Special to the S.F. Examiner)

Sergeant cleared in shooting of man on meth ‘rampage’

A San Francisco police sergeant has been cleared of criminal wrongdoing for shooting a “crazed, drugged out man” who had blood on his pants that belonged to the victim of an Outer Sunset homicide, prosecutors said Thursday.

The sergeant, identified for the first time as William Pon, was getting gas at a Chevron station in South San Francisco while off-duty on Easter Sunday when he stopped 35-year-old Justin Silvernale from attacking a man and shot him.

Silvernale still managed to steal a responding police vehicle before being shot and killed by three South San Francisco police officers. Investigators later found the blood and identification of 41-year-old Catono Perez on his body.

Weeks after the shooting, San Francisco police found human remains and a large pool of blood at Perez’s apartment on Great Highway between Moraga and Lawton streets on April 26. His mother had reported him missing and called 911.

The Medical Examiner’s Office has since confirmed the remains belonged to Perez.

On Thursday, San Mateo County District Attorney Steve Wagstaffe declined to file charges against Pon or South San Francisco officers Andrew Hyde and Michael Valdes and Corporal Chris Devan for shooting at Silvernale.

He praised them all for exercising restraint until it was reasonable and necessary to use deadly force to defend human life.

“Sergeant Pon stepped in when Silvernale was attacking an innocent member of the public and suddenly found himself the victim of an assault with a bladed box cutter,” Wagstaffe wrote in a letter to Police Chief Bill Scott.

“He showed remarkable restraint in not immediately shooting the attacker but instead fending off the knife with his arm,” Wagstaffe said. “He was himself slashed and only when the attacker came at him again did he use his firearm.”

It’s unclear whether homicide investigators have concluded Silvernale was a suspect in the Perez homicide. San Francisco police did not immediately respond to a request for comment.

KTVU first reported the possible connection between Silvernale and Perez. The outlet also reported via anonymous sources that a severed head was found in Perez’s refrigerator.

The police shooting unfolded at around 5:30 a.m. April 12 at the Chevron gas station on Hickey Boulevard and El Camino Real after Pon heard a 56-year-old man screaming for help, according to the District Attorney’s Office.

Silvernale had stolen a rental car from San Francisco International Airport but all four tires were punctured. He parked near the gas station and pulled the victim out of an SUV, punching and kicking him repeatedly.

A fight ensued when Pon, wearing civilian clothes but with a badge hanging around his neck, drew a gun on Silvernale and ordered him to stop. “Sergeant Pon described Silvernale as having a ‘thousand-yard stare’ and appearing like a wild animal,” Wagstaffe wrote in his letter to Scott.

Pon tried to control the situation with his fists when Silvernale charged him, putting his gun away and punching him, but then Silvernale slashed him across the side of his head with a box cutter.

“Go ahead and kill me, kill me,” Silvernale said when Pon drew his gun again and warned that he would shoot, according to Wagstaffe.

Pon fired once as Silvernale advanced toward him, striking Silvernale in the lower abdomen, Wagstaffe said.

“On several occasions, Sergeant Pon retreated to maintain a safe distance as he continued to issue commands to Silvernale,” Wagstaffe wrote. “It was only when Sergeant Pon realized that Silvernale was armed with a knife and was intent on injuring and possibly killing him that Seargent Pon rightly concluded that deadly force was necessary.”

When South San Francisco police officers responded to the gas station at 5:35 a.m., Hyde used a Taser stun gun to bring Silvernale to the ground twice.

But Silvernale got back up and, when the officers increased their distance with him in an attempt to de-escalate the situation, stole a patrol vehicle.

The officers pursued Silvernale for less than a mile to Kaiser Medical Center where he accelerated through a metal gate into an underground parking lot.

A second encounter then ensued, with Silvernale attempting to strike Hyde with his car, Wagstaffe said in a letter to South San Francisco Police Chief Jeff Azzopardi.

When Devan ordered Silvernale out of the vehicle, he exited with the knife in his hand.

“Silvernale ignored repeated orders by the officers to drop the knife and get on the ground as he charged toward the officers,” Wagstaffe wrote. “As he got within 15 feet of them, Officer Hyde fired one round from his shotgun while Corporal Devan and Officer Valdez fired five and four rounds respectively at him.”

The officers later said they feared for their lives and had either exhausted or could not use less-lethal options.

Hyde said Silvernale appeared to be on a “rampage,” according to Wagstaffe.

“Whether he was seeking to end his life by provoking the officers to [use] lethal force cannot ever be definitively known, but it is a reasonable conclusion that this was Mr. Silvernale’s goal on that Sunday morning,” he wrote.

A toxicology report later revealed “high levels of amphetamine and methamphetamine in Silvernale’s blood,” Wagstaffe said.

He died as a result of multiple gunshot wounds to his torso and also was shot in the legs and pelvis.

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