Los Angeles  - The man who allegedly killed his wife and five children earlier this week had been fired from his job at a local hospital, along with his wife, for allegedly forging a supervisor's signature on an application for free child care, the Los Angeles Times reported Thursday.

The murder-suicide on Tuesday sent shockwaves through Los Angeles, where it was seen as another example of the devastating human impact of the economic downturn.

In a letter sent to police and local media at the time of the murders, Ervin Lupoe said that killing the family seemed the only option after he and his wife had been fired from their jobs as medical technicians.

"Why leave our children in someone else's hands ... we have no job and 5 children under 8 years with no place to go. So here we are," Lupoe wrote.

Until Thursday's report it was unclear why the couple had been fired. But an official at the Kaiser Permanente hospital group said that Ervin and Ana Lupoe had falsified income records in order to qualify for a discounted child care programme.

"They were terminated because in the healthcare field records are an important part of the process and people trust us with their health," said Diana Bonita, the group's vice president for public affairs.

The report quoted police sources as saying that the Lupoes tried to make it look as though they earned between 7 and 10 dollars an hour, when in reality they each earned about 40 dollars a hour.

Police believe Lupoe used a handgun to kill his twin two-year-old sons, his twin five-year-old daughters, his eight-year-old daughter and his wife at his Los Angeles home Tuesday morning, before alerting police and then turning the gun on himself. (dpa)