The killings of serial killer Lonnie David Franklin Jr., also known as Grim Sleeper, featured on The Face Of Evil

The Face of Evil on Investigation Discovery takes a closer look at the case of Lonnie David Franklin Jr., an American serial killer known as Grim Sleeper.

From 1985 to 2007, there was a slew of murders that took place in the alleyways of Los Angeles, California — the victims were mostly prostitutes and drug addicts.

The killer was dubbed Grim Sleeper because the killing stopped in 1988, then resumed in 2002.

Police officials identified the Grim Sleeper as Lonnie David Franklin Jr. in 2010 through DNA technology. When his son, Christopher Franklin, was arrested in 2008, they collected a sample of his DNA and it showed genetic similarities to the DNA evidence collected at multiple murder scenes; therefore, they knew the killer had to be a relative.

Authorities said an undercover officer posed as a waiter to collect Franklin’s DNA from a pizza crust he had left behind at a restaurant, where he attended a birthday party. His DNA was a match, and Franklin was arrested on 10 counts of first-degree murder and attempted murder.

During a three-day search of Franklin’s home, they found a handgun, over 500 images of women who appeared to have been unconscious or dead, x-rated videos of unconscious women, and items that may have belonged to his victims — it was all found hidden behind a wall.

Franklin, who worked as a city trash collector and one-time garage attendant for the Los Angeles Police Department at the time of the killings, was later convicted of murdering nine women and a 15-year-old girl; however, police officials believe that Franklin may be linked to more killings, but there isn’t any evidence to convict him.

The Grim Sleeper’s victims were shot to death.

Although Franklin maintained his innocence, Los Angeles County Superior Court Judge Kathleen Kennedy sentenced Grim Sleeper to death by lethal injection.

The Face of Evil — The Grim Sleeper, airs at 10/9c on Investigation Discovery.