Teen Who Claimed Autistic Brother Killed Dad Before Shootiing Himself Will Spend Life In Prison For Double Murder

A California teenager who fatally shot his father and autistic brother and then tried to cover up the crime as a murder-suicide will spend the rest of his life in prison.

Robert Cotter, now 19, had initially told the investigators that his 15-year-old brother, Brian Cotter, fatally shot their father, 53-year-old Patrick Cotter, and then killed himself inside their Fresno mobile home in May last year.

"He called 911 and he blamed his murders as a murder-suicide perpetrated by his 15-year-old brother with autism spectrum disorder," said prosecutor Daniel Walters.

However, investigators got suspicious of Robert’s story when they checked his internet browsing history and learned that he had searched for how to make a murder look like a suicide, reports said.

Robert then waited for his father and brother to go to sleep on May 16, before shooting his dad first, according to the Fresno Bee.

"His brother woke up, started to run away and he pulled his brother by the collar and shot him in the head," said Walters.

The teen initially pleaded not guilty by reason of insanity but admitted his crimes early in the process.

During the trial, Robert’s attorney said the teen had been "traumatized" by an abusive childhood.

"Mr. Cotter had a difficult upbringing," said Emily Takao. "I think it would be characterized as traumatic."

Even if the teen had a traumatic life, his decision to kill his autistic brother wiped away any chance of leniency, the judge said.

"I don't know what his issue was with his father that caused him to want to commit homicide, but to execute his brother?" said Judge James Kelley. "It was the cold-blooded murder of a kid that had done nothing wrong."

Robert was sentenced to life in prison without parole for the murders on Monday, June 20, plus 50 years to life for using a gun, TV station KFSN reported.