East Palo Alto Police Officer Richard May did not use excessive force when he struck fleeing suspect Alberto Alvarez with a baton, a use-of-force expert testified Thursday in Alvarez' murder trial in San Mateo County Superior Court.

He may even have used too little, Lt. David Rose, an expert in impact-weapon recognition and police use of force, testified. He said May was already "behind the curve" when he struck Alvarez with a retractable metal baton (called an ASP) rather than drawing his gun.

The decision to go with the lesser use of force might have cost May his life, Rose said.

"It's unfortunate he didn't know it at the time, but he brought a baton to a gunfight," Rose said.

Studies show by the time a suspect pulls out a gun, if the officer's weapon isn't already drawn the officer would probably only get off one shot before the suspect could shoot four or five times, Rose said.

Alvarez, 26, faces first-degree murder charges with special circumstances for the Jan. 7, 2006, shooting death of May. If convicted, Alvarez could face the death penalty or life in prison.

In calling Rose, prosecutors sought a pre-emptive strike against defense arguments that May allegedly used excessive force against Alvarez.

The defense claims May pursued the defendant with unjust cause while responding to a dispatch call about a fight at a taqueria. Another man who started the fight attacked Alvarez, witnesses said.

Prosecutor Steve Wagstaffe queried Rose, taking him step-by-step through the encounter between May and Alvarez. He asked for detailed explanations on whether every action by the officer was justified. Rose said they were.

May followed police protocol when he followed Alvarez in his patrol car,
after receiving a dispatch call about a fight in a nearby taqueria, Rose said.

He said the body language Alvarez used, was described by May's ride-along companion, 16-year-old police Explorer Marco Marquez, as nervous and suspicious. Combined with a dispatch description of a Hispanic suspect of Alvarez's age wearing a black jacket, there was probable cause for the officer to stop and question Alvarez, he said.

Defense Attorney Charles Robinson asked Rose, a retired Placer County law-enforcement officer, if he was familiar with East Palo Alto's demographic. Rose said he was not.

"How many Hispanic 22-year-old males wearing black jackets do you think there are in East Palo Alto?" Robinson asked.

Robinson said Alvarez did not fit the suspect's description. Dispatchers described the fight's perpetrator as wearing a black jacket but no shirt. Surveillance video as Alvarez fled the shooting, shows he was wearing a shirt with extended tails below his jacket.

May stopped his police car and stepped out with one leg, which was sufficient communication to Alvarez that the officer wanted "consensual contact," Rose said. But Alvarez took off running away from the officer and across University Avenue to Weeks Street. Rose said at that point Alvarez committed a misdemeanor by fleeing the officer.

"The law says you do not have to stop for a police officer just because he tells you to stop," Robinson said, citing U.S. Supreme Court decisions.

There would have to be a reason, he said. Rose agreed.

"If you get out of a police car and don't say a word to me, why would I know you want to talk to me?" Robinson said.

Rose hesitated. "Based on body language, I guess," he said.

Rose said any flight could be considered aggressive rather than passive, and May acted properly when he abruptly turned his squad car around and followed Alvarez to nearby Weeks Street, where the shooting occurred.

"A reasonable officer is obligated to take action," after Alvarez attempted to enter an apartment complex, fumbling his keys. The officer should be concerned the suspect could hide in an apartment and barricade himself in or take a hostage, he said.

Rose called taking out the baton "a visual persuader" to stop a person or to have ready to use if the suspect failed to stop.

May shouted in a strong voice, "I would stop if I were you," Marquez testified previously.

At that point, Alvarez committed a misdemeanor when he ran from May after the officer made it clear he wanted him to stop, Rose said.

Robinson argued May had violated East Palo Alto Police Department policy, which requires an officer to use the least possible force and lists an order of force to be used.

"Officers shall use their impact weapons as a defensive weapon to overcome resistance or to control violent persons," the policy states.

"What aggressive move was Mr. Alvarez exhibiting?" Robinson asked, noting at that point Alvarez had only fled the officer.

But state law and city policy also allows for discretion by the officer to decide which level of force is necessary, Rose said.

When an officer faces a larger and younger suspect, such as Alvarez, tackling him would be hazardous, he said.

May's strikes on Alvarez were likely ineffective because he hit Alvarez on the fleshy part of his upper arm rather than a bony area such as a knee, he said.

"It can look like a person was beaten to a bloody pulp but the (suspect)
never stopped," he said.

"In reality, (the officer) reaches a split-second decision. There is a saying -- that it happens in an eye blink or it happens in a heart beat," he said.

Robinson attacked Rose's credibility, reading passages from "The Paradigm of a Moral Warrior," a book Rose co-authored. It was written for police officers, military personnel and civilians to teach "a strong warrior mentality," according to Rose's website.

"If we can intimidate the other side badly, we can bring about deterrence," Robinson read.

Wagstaffe rose from his seat, vigorously opposing the reading. It had nothing to do with the trial, he said.

"I'm trying to show his frame of mind," Robinson countered.

San Mateo Superior Court Judge Craig Parsons allowed the readings. But after several passages and Wagstaffe's continued opposition, Parsons instructed Robinson to go no further.

One defense witness who would not be available next week when the defense presents evidence was allowed to take the stand Thursday afternoon.

John Maness, chief of San Mateo County's private defender's office investigating division, showed video clips from Alvarez's arrest booking. Three clips showed Alvarez signing documents with his left hand.

Prosecutors and witnesses have said Alvarez shot May using his right hand.

Maness also discussed surveillance video from a security camera outside PAL Market, located in the same strip mall as the taqueria.

The video was synchronized with audio of the 911 call about the fight, police dispatch and May's patrol car.

Alvarez can be seen walking calmly out of the taqueria to the corner of Cooley and University avenues. As he crosses the street starting to run, May's patrol car makes a U-turn, traveling against traffic and swerving through a gap in a traffic island, in pursuit of Alvarez.

Approximately 32 seconds after the patrol car took off to pursue Alvarez, 17 seconds after May told Alvarez, "I'd stop if I were you," May was dead.

"Man down! Man down!" Marquez is heard shouting.