Los Angeles - An unemployed financial advisor killed himself and five family members in a posh Los Angeles suburb Monday in a crime that police said was likely linked to his financial despondency, the Los Angeles Times reported.

The suspect, aged 45, was names by neighbours as Karthik Rajaram. According to police he killed his wife, mother-in-law and three children before taking his own life in the gated community of Porter Ranch in the north-west San Fernando Valley.

"We believe this to be a murder-suicide," said Los Angeles Police Department Deputy Chief Michael Moore said. "It appears (the gunman) killed his family and then took his own life."

The bodies of the man's 39-year-old wife, 70-year-old mother-in- law, and three sons - ages 19, 12 and 7 - were found inside the home's bedrooms.

Moore said it appeared that the gunman shot the victims Saturday night and left three letters admitting to the killings. He said the gunman had worked previously for Price Waterhouse and Sony Pictures and "had attested to some financial difficulties," Moore said. "He had become despondent over his financial" situation.