Thelma Kibble (b. 1957) is a probation officer in Los Angeles County, California, and a resident of Hawthorne. She works in the Van Nuys office.
In 1999, she was assigned the parole case for Cassie Black, who had transferred from Las Vegas to California. Later that year, she was shot in the chest by private investigator/hitman Jack Karch inside Black's house. Black returned home to find Kibble in her closet, severely wounded. She called 911 for Kibble and then disappeared. Kibble was treated at Cedars-Sinai Medical Center and recovered, returning to work in mid-January of 2001.
In May of 2005, Kibble was interviewed by LAPD cold-case detectives Kizmin Rider and Harry Bosch after a DNA sample from a 1988 murder weapon matched a suspect who had served his parole under Kibble.