Brandon Willie Martin, 27, killed 64-year-old Michael Martin, along with the elder man's brother-in-law, 51-year-old Ricky Lee Anderson of Corona, and 62-year-old Barry Swanson of Riverside on the evening of Sept. 17, 2015.
After deliberating less than a day, a Riverside jury convicted Martin of the murder counts, found true a special circumstance allegation of taking multiple lives in the same crime, and further convicted him of one count each of auto theft, evading arrest, obstructing a peace officer and injuring a police canine.
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Riverside County Superior Court Judge Bernard Schwartz scheduled the penalty phase of trial to get underway Monday morning at the Riverside Hall of Justice. The District Attorney's Office is seeking capital punishment for the defendant, who's being held without bail at the Robert Presley Jail in Riverside.
Testimony in the guilt phase of trial spanned just over a week, with closings by the prosecution and defense Tuesday.
According to the prosecution, Martin had been experiencing unspecified psychiatric issues and was admitted to the county Department of Mental Health's emergency treatment facility on County Farm Road during the night of Sept. 15, 2015, for an evaluation. His admission came after he'd made threats against his disabled father.
The defendant was released from the facility two days later and went straight to the elder man's residence in the 1000 block of Winthrop Drive, arriving shortly after 6 p.m.
The victim was at the property with Anderson and Swanson, an ADT alarm company technician who was there for an installation consultation, stemming directly from concerns about safety in the face of the defendant's threats, according to prosecutors.
Brandon Martin grabbed a baseball bat inside the house and went on a rampage, pummeling all three men. Michael Martin and Swanson died at the scene, but Anderson lingered in a coma for two days before dying from his injuries.
After the attack, the defendant stole Swanson's Ford Raptor pickup and hid out overnight.
According to Corona police Sgt. Brent Nelson, an off-duty officer spotted the truck in the area of Lincoln and Mountain avenues early the next morning and attempted to stop it, but Martin fled onto Derby Street, dodging several patrol vehicles whose officers tried to disable the Ford using intervention maneuvers.
The defendant bailed out of the truck at the intersection of Darby and Buena Vista Avenue, near Foothill Elementary School, and darted into a home, where a woman was taking a shower. Martin tried to escape by leaping from a second-story window but encountered a K-9 officer and his dog, culminating in a brief struggle before he was forcibly taken into custody, according to Nelson.
The woman was not injured.
The defendant graduated from Santiago High School in 2011 and was selected in the first round of that year's Major League Baseball draft by the Tampa Bay Rays, the 38th overall selection. Martin played three seasons for the Rays' farm team and was let go on March 26, 2015.
He had no documented prior felony convictions.