Nov. 6 (UPI) -- Prosecutors say they will seek the death penalty Monday against former Major League Baseball prospect Brandon Martin in the 2015 triple murder of his father, uncle and a home alarm installer.
Martin, once a top prospect for the Tampa Bay Rays, was convicted in the slayings Wednesday.
He had been on a mental health hold two days before the slayings. The family was installing an alarm system on Sept. 17, 2015 at their Corona, Calif., home after he repeatedly displayed violent behavior toward them.
Authorities said Martin had to be forcibly taken into custody the day after the murder when they confronted him.
Hailed as the "next Derek Jeter," the New York Yankees superstar, Tampa Bay made Martin the 38th overall pick in the 2011 draft. His erratic behavior led him to be let go by the team on March 26, 2015, after three years in their farm system.
Authorities said Martin fell into drugs after winning a contract of nearly $1 million from the Rays. He often held parties with large entourages during the season and grew angrier at his father, once punching him in the head.
He had choked his mother and held scissors to her neck in 2015, leading to the mental health hold two days before the slayings, authorities said.