Lisa Knox vanished from the 1000 block of 22nd Street in Los Angeles, California on May 11, 1993, and has never been seen or heard from since.

Her family believes she may have fallen victim to the Grim Sleeper killer. The Grim Sleeper murders started in the mid-1980s and abruptly stopped, but then resumed again in 2002. All of the victims were African-American women . Lonnie David Franklin Jr. was charged in 2010 with ten of the Grim Sleeper murders, as well as one attempted murder. He was convicted of all charges in 2016 and sentenced to death. However, authorities believe that he may have killed up to 25 women. Franklin passed away from natural causes on death row in California in 2020.

The families of Cathern Davis, Rosalind Giles, and Anita Parker, who are all missing, think that they may have also fallen victim to the Grim Sleeper killer. They were known to be involved in prostitution and drugs, and frequented areas near Franklin's residence where his suspected victims were found.

Though Lisa Knox has not been identified as a Grim Sleeper victim, her case is still being investigated, and her disappearance remains unsolved. It is believed that there may be additional victims of the Grim Sleeper killer.