LOS ANGELES, California (CNN) -- A man distraught because he could not find work shot and killed his mother-in-law, his wife and three sons and then killed himself inside a home in an upscale San Fernando Valley neighborhood, police said.

Police say Karthik Rajaram left suicide notes taking responsibility for the murders of his family.

Authorities said the man had an MBA in finance but appeared to have been unemployed for several months and had worked for major accounting firms, such as Price Waterhouse.

The two-story rented home is in a gated community in Porter Ranch, about 20 miles northwest of Los Angeles.

The shootings were discovered after 8:20 a.m. Monday, after a neighbor called police to report that the wife had failed to pick her up to take her to her job at a pharmacy, Deputy Chief of Police Michel Moore said.

Ed Winter, assistant chief from the Los Angeles County Coroner's Office, identified the suspect as Karthik Rajaram, 45.

Winter said the victims included Rajaram's mother-in-law, Indra Ramasesham, 69, and his 19-year-old son Krishna Rajaram, a Fulbright Scholar and honor student at UCLA. Watch police remove body from home »

Also dead were Rajaram's wife, 39, Subasari Rajaram, and their two other sons, 12 and 7. Some of the victims had been shot more than once, and their identities were not immediately confirmed, he said.

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"Due to the nature of their injuries, it's been a little difficult," Winter said, adding that there were no signs of a struggle.

Police first found the mother-in-law shot in her bed in a downstairs bedroom, Moore said.

Upstairs, the couple's eldest son was shot in the master bedroom; the wife in another bedroom with a gunshot wound to the head; the two younger sons in the bedroom they shared, both shot in the head. The 12-year-old was on the floor and the 7-year-old in bed, Moore said. Watch more on what police had to say about tragedy »

The suspect was also in that bedroom, a gun still in his hand.

The killings are thought to have occurred after 6 p.m. Saturday, when the man was last reported seen, Moore said.

Inside the house, police also found three letters, one to law enforcement acknowledging responsibility for the killings, a second to friends and relatives and a third that appears to be the suspect's will, Moore said.

"He attests to some financial difficulties, and he takes responsibility for the taking of the lives of his family members and himself as a result of those financial difficulties," Moore said.

Neighbors, family and friends told police that the suspect, who had not worked for several months, had said in recent days he was having had extreme financial difficulties, Moore said.

One of the letters, intended for friends and marked "personal and confidential," detailed his financial transactions that resulted in "an unfortunate, downward spiral," Moore said.

"His narrative is one of talking about this tragedy befalling him and his contemplation of an available exit or solution," Moore said. "One is taking his own life and the other is taking the lives of his family and himself. ... He talked himself into the second strategy, believing that was, in effect, the honorable thing to do."

Moore said the several-page narrative appeared to have been written over a period of time. "This was something that was not a spur-of-the-moment type of event," he said.

Moore said it was clear to police that the family members were close and "had an affection for each other." He said the parents had given up their master bedroom to their eldest -- who was spending the weekend home from college -- "out of respect."

"This is a perfect American family behind me that has absolutely been destroyed, apparently because of a man who just got stuck in a rabbit hole, if you will, of absolute despair, somehow working his way into believing this to be an acceptable exit."

No neighbors reported having heard gunshots, and there was no sign of forced entry at the house, Moore said.

Rajaram was involved in a financial holding company as part owner "at least," Moore said.

There is no evidence he had had any history of mental difficulties, nor was there an indication he had sought counseling, Moore said.

Neighbor Trish Harrison, who lives three houses from the crime scene, said the family had lived in the community for about a year, but kept to themselves and had little interaction with neighbors. The parents were from India, she said.

The Los Angeles Unified School District was making arrangements for crisis counselors to visit the schools attended by the two younger sons.

CNN's Stan Wilson contributed to this report.

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