Four days after a gunman opened fire on his co-workers before committing suicide at a utility office east of Los Angeles, investigators struggled to find a motive for the rampage.
Andre Turner methodically shot co-workers with a semiautomatic handgun then killed himself Friday inside the complex that houses more than 1,000 Edison employees, authorities said.
Turner had previously received a verbal reprimand for missing an audit deadline, sheriff's Lt. Holly Francisco said in a statement late Monday, but the exact timing of the reprimand was not clear.
The two men killed were Henry Serrano, 56, of Walnut, and Robert Scott Lindsay, 53, of Chino Hills, coroner and company officials said. Turner and Lindsay died at the scene. Serrano died while being taken to a hospital, the coroner's office said.
Abhay Pimpale, a 38-year-old independent contractor from Montebello who was shot but survived the shooting, declined to comment. Pimpale, the father of a 3-year-old son and a newborn baby, was released from the hospital Saturday.
He told KCAL-TV he only wanted to "spend time with my family."
A fourth victim, 46-year-old Angela Alvarez, was upgraded from critical condition to serious condition at County-USC Hospital on Monday, said spokeswoman Rosa Saca.
In a 911 call released by authorities Monday, the operator says she could hear what was possibly gunfire while the security guard from the office park called to report the shooting.
"I heard a male voice in the background yelling," the operator said. "There's also some loud popping noises in the background."
Turner's death was ruled a suicide. A systems analyst at Edison, he had worked at the company for seven years, utility spokesman Steven Conroy said.
Turner's wife, Jean Turner, wrote in a brief statement given to KTLA: "We are in shock and still trying to process this tragic event. Our hearts and prayers go out to all the victims and their families."
While a motive was not clear, The Press-Enterprise reported Sunday that Turner bought a 5,000 square-foot, five-bedroom house near Hidden Valley Golf Club for $711,000 when it was new in 2004.
The Riverside County assessor's office shows its current value as $543,000 and it was put up for sale in November for $590,000, the newspaper said.
The shooting victims were all in supervisory roles at Edison, but it's unclear whether any of them were Turner's direct supervisors, Los Angeles County sheriff's Lt. Holly Francisco told KCAL-TV.
Lindsay was a manager in the IT division at Edison and worked for the company for 29 years, company officials said. He was married and was a father. Serrano, a manager in the same area, was with the company for 26 years.
All five people worked in the same area of the same building at the office park in Irwindale, a small industrial city in the San Gabriel Valley, authorities said.
Edison said it was offering grief counseling for employees and is establishing a fund to support the victims' families. The company will donate $100,000 and seek employee contributions.
Southern California Edison said Monday it has stepped up security, but declined to provide details. The Irwindale facility remains closed to workers.
Associated Press writers Noaki Schwartz, Shaya Tayefe Mohajer, Christopher Weber and Denise Petski in Los Angeles, and Greg Risling in Irwindale contributed to this report.