John Floyd Thomas Jr. was born in Los Angeles, California. His early life was marked by tragedy when his mother died when he was just 12 years old. After her death, Thomas was raised by his aunt and a godmother, providing him with a somewhat unstable home life. He attended public schools in Los Angeles, including Manual Arts High School, but his school years were not particularly noteworthy.

In 1956, Thomas joined the U.S. Air Force, hoping for a fresh start. He was stationed at Nellis Air Force Base in Nevada. However, his time in the military was troubled. His superiors often noted that he was frequently late and sloppy in his appearance.

These issues led to him receiving a dishonorable discharge from the Air Force. This marked the beginning of a difficult and troubled path for Thomas. After his discharge, Thomas returned to Los Angeles. His behavior soon led him into serious trouble with the law. He was arrested for burglary and attempted rape, crimes that led to his conviction in 1957. He was sentenced to six years in the California state prison system. Due to parole violations, his time in prison was extended, and he remained behind bars until 1966. This period of incarceration set the stage for the dark and violent path Thomas would later follow.

In the mid-1970s, Los Angeles police were hunting for a serial killer who preyed on elderly women living alone. The killer, known as the "Westside Rapist," would break into their homes, assault them, and then strangle or suffocate them, often covering their faces with pillows or blankets. By 1978, at least 17 women had been murdered, and the attacks suddenly stopped, leaving the community in fear but with no answers.

Years later, in the mid-1980s, a similar pattern of murders appeared in the Pomona Valley. This time, the killer was called the "Southland Strangler," and he continued the brutal method of using pillows or blankets on his victims. At least five more women were killed, but these cases were not initially connected to the earlier ones. Again, the killings stopped in 1989, leaving more than 20 unsolved murders and a community still in the dark.

The breakthrough came in 2001 when the LAPD launched a unit to reopen cold cases using new DNA technology. They found biological evidence in the murder of 68-year-old Ethel Sokoloff from 1972 that had not been examined before. By 2005, this evidence was linked to other cases, including the 1976 murder of Elizabeth McKeown. In 2009, a DNA match identified the killer as John Floyd Thomas Jr., a man with a history of burglaries and sexual assaults. Arrested and charged with multiple murders, Thomas was eventually linked to at least seven deaths and suspected in many more. He was sentenced to life in prison without the possibility of parole in 2011, finally ending a decades-long search for one of Los Angeles' most elusive serial killers.