George Emil Banks was born on June 22, 1942, in Wilkes-Barre, Pennsylvania. His father, John Mack, was black, and his mother, Mary Yelland, was white. His parents were not married, and growing up, Banks faced challenges related to his mixed-race identity. According to his attorneys, he experienced severe racism during his childhood.

In 1961, at the age of 19, Banks was discharged from the Army. Shortly after, he was involved in a robbery with some accomplices. During this crime, they shot and injured an unarmed tavern owner. For this, he was sentenced to six to fifteen years in prison. His sentence was extended when he briefly escaped in 1964. However, he was granted parole in 1969 and had his sentence commuted by Pennsylvania Governor Milton Shapp in 1974.

After his release, Banks married Doris M. Banks on August 23, 1969. The couple had two daughters together, but they divorced in 1976. Following the divorce, Banks began dating white women. By September 1982, he had recently ended a relationship with Sharon Mazillo, with whom he had a son. He was living with three women who were the mothers of four of his children.

Despite having a criminal record, Banks managed to work as a correctional officer at Camp Hill, Pennsylvania, starting in 1980. In 1982, he expressed troubling thoughts to his coworkers, mentioning a coming "race war" and his concerns for his children regarding racism. After a conflict with a supervisor and threatening suicide, he was put on an extended leave of absence and ordered to undergo mental health evaluation at a hospital in Harrisburg.

On September 25, 1982, George Emil Banks carried out a mass shooting in Wilkes-Barre, Pennsylvania. The night before, he consumed a large amount of gin and took prescription drugs. The next morning, he used an AR-15 semi-automatic rifle to kill eight people in his home. The victims included three of his girlfriends, all in their twenties, and five children, four of whom were his own.

After the shootings at his house, Banks went outside and shot two men, Jimmy Olsen and Ray Hall Jr., who were leaving a nearby house. Hall was fatally wounded, but Olsen survived. Following this, Banks drove away from the scene. He then traveled to a mobile home park where his former girlfriend, Sharon Mazzillo, and their son, Kissamayu, lived. Banks forcibly entered the home and shot Mazzillo, followed by their sleeping son. He also killed Mazzillo's mother and her nephew while another relative hid in the closet. This relative was the only survivor from that house.

After the shootings, police found the victims at both the mobile home and Banks's home. They began searching for Banks, who abandoned his car and stole another vehicle before stopping to rest in a grassy area. He later visited his mother’s house, where he reportedly confessed to her about the murders. Banks then sent his mother away and prepared for a standoff with police.

The standoff lasted for four hours. Police attempted various strategies to persuade him to surrender, including bringing in his mother and playing a false news report. Ultimately, a former co-worker successfully convinced Banks to come out. By September 30, 1982, he was charged with multiple counts of murder and held without bail.

In June 1983, Banks' trial began. He testified and claimed that he only wounded some victims and that police had killed the rest. However, he was found guilty of twelve counts of first-degree murder and sentenced to death. He was incarcerated in a maximum-security unit and remained on death row in Pennsylvania for many years.

Over the years, Banks's attorneys filed several appeals regarding his mental competence. He was found mentally incompetent for execution on multiple occasions. In 2010, a judge ruled again that he could not be executed or assist his lawyers in their efforts for clemency. As of September 2017, Banks was still in a restricted housing unit. In May 2018, he was transferred to another facility.