Cimarron Bernard Bell was born on April 7, 1974, in South Whittier, California. He grew up in a community that is part of Los Angeles County. Not much is known about his early family life or childhood. However, he lived in a typical American environment during his formative years.

As a young adult, Bell had various jobs. At one point, he worked as a janitor at the Morgan Metals industrial park. While employed there, he became involved in illegal activities, including a check-cashing scheme. This operation included his girlfriend, Ineka Edmondson, who was 22 years old at the time.

Cimarron Bernard Bell committed a series of murders in California between 2003 and 2004. His first known victim was his girlfriend, Ineka Edmondson. On November 11, 2003, Bell shot her three times in the head. After Edmondson's body was discovered the next day, investigators had no solid evidence linking Bell to her murder.

Soon after, Bell and his accomplice, Briaell Michael Lee, devised a plan to lure potential victims to Bell's house. They advertised Bell's modified Chevrolet Monte Carlo for a price much lower than its actual worth. On January 27, 2004, they invited three men—Mario Larios, Fernando Pina, and Edgar Valles—to view the car. Once inside, Bell and Lee shot all three men. They concealed the bodies in Bell's Mercedes-Benz. To dispose of the evidence, they later abandoned the car in a parking lot in La Mirada.

The police were alerted after a passerby discovered the bodies due to a bad smell coming from the vehicle. Investigators traced the last movements of the victims back to Bell's home. His capture became more likely when another girlfriend of Bell informed the police about his admissions of murder. Bell was arrested on February 14, 2004.

During the trial, Bell and Lee both pleaded not guilty to the charges of murder. However, after months of proceedings, the jury found Bell guilty of four murders, including that of Edmondson. He was sentenced to death on April 19, 2011. Lee was convicted of only one count of second-degree murder and received a sentence of 40 years to life in prison. Bell has made several unsuccessful attempts to appeal his sentence and remains on death row.