Leonard Lake was born on October 29, 1945, in San Francisco, California. His parents separated when he was six years old. After their separation, Leonard and his siblings were sent to live with their grandparents. This major change in his early life greatly affected him.

Living with his grandparents, Leonard developed some disturbing behaviors. He enjoyed taking pictures of his sisters while they were undressing and became obsessed with pornography. His interest in violence and control started to grow during this time.

In his teenage years, Leonard joined the Marine Corps. However, his time in the military did not change his troubling behavior. After serving in Vietnam, he was discharged due to psychological issues.

Returning to civilian life, Leonard struggled to find stability. He got married, but his marriage quickly fell apart. He continued to engage in illegal activities, including stealing cars. These early signs of his criminal behavior hinted at the darker crimes he would commit later in life.

Leonard Lake, together with his partner Charles Ng, committed a series of brutal crimes in the early 1980s. They targeted men, women, and sometimes entire families, luring them to a remote cabin in Wilseyville, California. Here, they had built a secret bunker where they carried out their horrific acts.

Lake and Ng are believed to have killed between 11 and 25 people. Their victims included Leonard's own brother, neighbors, and people they tricked through newspaper ads. They often stole their victims' identities and used their money. The police found videotapes showing some of the terrible things they did to their victims, which included torture and murder.

The crime spree ended on June 2, 1985, when Charles Ng was caught stealing from a store. Leonard Lake tried to pay for the stolen item, but police found an illegal gun in his car and arrested him. While in custody, Lake swallowed cyanide pills he had hidden in his clothes. He was taken to the hospital but died four days later without waking up.

After Lake's arrest, the police searched his property and found human remains, including bones and ashes. They discovered a diary where Lake had written about his plans and videotapes showing his crimes. The evidence showed the full extent of the horrible things he and Ng had done.

Charles Ng was later captured in Canada and extradited to the United States. He was found guilty of multiple murders and sentenced to death. Leonard Lake's suicide prevented him from facing justice, but the evidence left behind told the story of his and Ng's terrible crimes.