Christopher Black Sr. was born on August 2, 1959, in Portsmouth, Virginia. He grew up in a military family, which influenced his later decisions. As a young man, he joined the U.S. Army, where he served for several years. During his time in the Army, he worked hard and earned a promotion to the rank of Sergeant before retiring.

In the mid-1990s, Christopher married Gwendolyn Black, who was also a retired Army soldier. Gwendolyn transitioned to a new career as an elementary school teacher. The couple had a daughter named Christina Marie Black, who was born in 1997.

In 1998, Christopher Black Sr. learned that his wife, Gwendolyn, wanted a divorce. Upset by this news, he planned to kill her and anyone else with her. He bought a 9mm semi-automatic pistol after waiting a few days for a background check. Christopher also recorded several cassette tapes where he expressed his anger and mentioned his plans for the murders. He mailed these tapes to relatives so they would arrive after the crimes.

On February 7, 1998, Christopher went to Gwendolyn's house in Killeen, Texas. There, he shot her ten times. A friend of Gwendolyn's, Deidre Blackburn, witnessed the shooting and managed to escape. After shooting his wife, Christopher turned the gun on his 5-month-old daughter, Christina Marie Black, and 17-month-old step-granddaughter, Katrese Houston, while Katrese was in her high chair. He shot Christina once and Katrese five times in the chest. Following the shootings, Christopher called 911 and admitted to the murders, telling the operator that he ran out of bullets.

When police arrived, they found Christopher holding Christina. He had dropped his weapon. An officer described how he wanted to kiss the baby before she was taken into custody. Unfortunately, she was already dead.

Christopher was arrested and charged with murder. To simplify the case, he was only tried for the murder of Katrese, as it was a capital offense due to her age. During the trial, he claimed that his wife abused him and his son.

In August 1998, the jury found Christopher guilty of capital murder after only 15 minutes of deliberation. They spent another seven hours deciding on the death sentence. While on death row, he did not grant any interviews, only expressing a desire for a friend in a letter.

Christopher Black Sr. was executed by lethal injection on July 8, 2003. When asked if he had any last words, he said he did not. After his execution, Gwendolyn's sister stated that they continue to miss their loved ones and would not be thinking about him.