A documentary about one of San Diego’s most infamous murders is scheduled to make its debut Tuesday night in the Gaslamp Quarter as part of the San Diego Film Festival.

Chelsea’s Light: A Brother’s Journey From Pain to Purpose will be screened at 7 p.m. at Reading Cinemas Gaslamp, 701 Fifth Ave.

The film depicts Tyler King, brother of slain Poway High School student Chelsea King, and his efforts to prevent crimes against children. Bruce Caulk, an Emmy-Award winning director, worked with him on the project, which was funded via Kickstarter, garnering $68,000, far above the original $50,000 goal.

Chelsea, a 17-year-old Poway High senior, was killed in 2010 after she was accosted by convicted sex offender John Albert Gardner III while jogging in the hills above Lake Hodges. Tyler was 13 when Chelsea was killed.

In the course of investigating the murder of Chelsea King, police learned that almost exactly a year earlier, Gardner killed Escondido High student Amber Dubois, 14.

Gardner – a registered sex offender long before he killed the girls – was convicted in 2000 of sexually molesting a 13-year-old neighbor.

He was sentenced to two consecutive life prison terms without the possibility of parole for the girls’ murders. He was also sentenced to 25 years to life for attacking a 22-year-old jogger two months prior to killing Chelsea, and received an additional 24 years because of various prior convictions.

Tyler, on his Kickstarter video, said he wanted to make his documentary “to help raise awareness and strengthen laws to keep these predators behind bars.”

Tyler is following his parents’ example in becoming an activist. After their daughter’s murder, Brent and Kelly King championed California’s Chelsea’s Law, which mandates life prison terms for those convicted of violent sex crimes against children and increases law enforcement oversight of paroled sex offenders.

The King family also launched a foundation in Chelsea’s name and an annual Finish Chelsea’s Run 5K event that draws thousands of runners.

– City News Service contributed to this report.