Lonnie Franklin, a convicted serial killer who is also known as the “Grim Sleeper”, was found dead inside a prison cell.

Franklin, who murdered and preyed on women in California for over 3 decades, was found dead inside a prison cell at the San Quentin State Prison.

Franklin was found unresponsive in his cell on the evening of Saturday.

According to a statement from the California Department of Corrections and Rehabilitation, the authorities are performing an autopsy to know the 67-year-old’s death cause.

There were no signs of trauma, said the statement.

Franklin used to work as a garage attendant at a Los Angeles Police Department Station and was also a former city trash collector.

The police have collected DNA from the crime scenes, however, they were unable to find a match for a number of years.

But everything changed when investigators found a similar match to Franklin taken from the scene on a second attempt to cross-reference a state databank of convicted felons’ DNA.

The match was his son.

The serial killer was placed on a 24-hour surveillance and a plan that was made to obtain his DNA.

An undercover officer posed as a waiter and collected a pizza crust that was left behind by Franklin.

The DNA on that crust came up as a match for the killer, which later gave him the name “the Grim Sleeper”.

The police arrested him in July 2010.

When the police raided his house in South Los Angeles, where they discovered photos and videos of 180 women.

Since that, the police have accounted for the identities and whereabouts of the women, however, 30 of the women still remain untraced.

The man was found guilty on 10 counts of first-degree murder and one count of attempted murder in the deaths of 9 women and 1 teenage girl.

Authorities believe the murders happened between 1985 and 2007.

Franklin was sentenced to death on August 10, 2016, in Los Angeles County.