Nathan Dunlap was born on April 8, 1974, in Chicago, Illinois. He was raised in a challenging environment, with his mother diagnosed with schizophrenia and bipolar disorder. Dunlap exhibited behavioral issues from a young age, including multiple suicide attempts during his adolescence.

He moved to Colorado in 1984 and attended Overland High School in Aurora. At 15, Dunlap committed several armed robberies, leading to time in juvenile detention and a psychiatric hospital. After his release, he continued to have run-ins with the law, including five misdemeanor arrests in 1993.

In May 1993, Dunlap began working at a Chuck E. Cheese restaurant in Aurora but was fired in July after a dispute over work hours. Friends and former colleagues noted his growing frustration and talk of "getting even" with the establishment.

On December 14, 1993, at approximately 9:00 p.m., Nathan Dunlap entered the Chuck E. Cheese restaurant in Aurora, Colorado, where he had previously been employed. He ordered a sandwich and played arcade games before hiding in a restroom around 9:50 p.m.

After the restaurant closed at 10:05 p.m., Dunlap emerged and began his attack using a .25-caliber semi-automatic pistol:
Sylvia Crowell (19): Cleaning the salad bar, she was shot in the right ear at close range.
Ben Grant (17): Vacuuming near the salad bar, he was fatally shot near the left eye.
Colleen O'Connor (17): Cleaning the quiet room, she was shot through the top of her head after pleading for her life.
Bobby Stephens (20): Returning from a smoke break, he was shot in the jaw but survived by playing dead.
Margaret Kohlberg (50): The store manager was forced to open the safe, then shot in the ear. Upon noticing her movement, Dunlap shot her again, resulting in her death.

Dunlap fled the scene with $1,500 in cash and game tokens. He was arrested approximately 12 hours later at his mother's apartment, where police recovered the murder weapon, ammunition, and gloves.

In 1996, Dunlap was convicted of four counts of first-degree murder, attempted murder, robbery, and burglary. He was sentenced to death and an additional 113 years for the other counts.

After exhausting his appeals, a warrant for Dunlap's execution was issued in 2013. However, then-Governor John Hickenlooper granted a temporary reprieve, citing concerns about the fairness of Colorado's death penalty system.

On March 23, 2020, Governor Jared Polis signed a bill abolishing the death penalty in Colorado and commuted the sentences of the state's death row inmates, including Dunlap, to life imprisonment without the possibility of parole.