David Paul Hammer was born on October 9, 1958. He was the oldest of three children in his family. David grew up in a household that was abusive and impoverished. His family's living conditions were difficult, and this environment affected his early years.

David's education was unstable. He did not stay in one school for very long. Over the years, he attended a total of 21 different schools. This frequent movement made it hard for him to build lasting friendships and succeed academically. At the age of 15, he dropped out of high school.

David Paul Hammer was involved in several serious criminal incidents. In September 1996, he was charged with the death of his cellmate, Andrew Hunt Marti, at the U.S. Penitentiary – Allenwood. The authorities alleged that Hammer strangled Marti with a piece of improvised cord in the Special Housing Unit where they were housed together.

In June 1998, during his jury trial, Hammer chose to plead guilty. He was sentenced to death on November 4, 1998. His execution was initially set for January 14, 1999. Despite initially accepting his fate, he later reconsidered and allowed his legal team to file an appeal. However, he changed his mind again and attempted to dismiss his own appeal.

Over the next few years, multiple execution dates were scheduled for Hammer. One of these dates was set for November 16, 2000, but a U.S. District Judge postponed it to allow for an appeal to be filed. In 2005, the district court vacated his death sentence due to the government withholding evidence that supported his defense.

In 2014, he was resentenced to life without the possibility of parole. During this time, the court found factors such as his acceptance of responsibility, family background issues, and mental health problems as reasons for a sentence less severe than death.

After his resentencing, Hammer served time in various facilities and faced severe health problems, including diabetes and sight issues. He was transferred to the ADX Florence, Colorado, known as a high-security prison. David Paul Hammer remained in prison until his death in June 2019.