Kenneth Biros was born on June 24, 1958, in the United States. 

Kenneth Biros admitted to killing 22-year-old Tami Engstrom in February 1991. He acted in a fit of rage. After the murder, he cut up her body and spread the parts over a wide area in northeast Ohio and northwest Pennsylvania.

Biros was convicted of several crimes, including aggravated murder, attempted rape, aggravated robbery, and felonious sexual penetration. He was sentenced to death. Biros was first set to be executed by lethal injection on March 20, 2007. However, his execution was stayed by the Supreme Court of the United States while he argued that Ohio's method of lethal injection was cruel and unusual punishment. He was then moved from Ohio's death row in Mansfield to the Southern Ohio Correctional Facility in Lucasville.

On April 24, 2009, the county prosecutor requested a new execution date after a federal judge decided that Ohio's execution method, while flawed, was not unconstitutional. The Ohio Supreme Court set Biros' execution for December 8, 2009.

Biros was executed by lethal injection on December 8, 2009, at 11:00 a.m. His execution was delayed until 11:00 a.m. He was pronounced dead at 11:47 a.m. Biros was the first person in America to be executed using a lethal dose of a single drug, sodium thiopental.