Robert Gregory Bowers was born on September 4, 1971, in Pittsburgh, Pennsylvania. When he was just one year old, his parents divorced. Bowers' father, Randall Bowers, died by suicide when Robert was only seven years old. This tragic event occurred in October 1979 while Randall was awaiting trial for a serious crime. After his father’s death, Robert's mother remarried, and the family briefly moved to Florida. However, the couple separated after a year, leading to more instability in his life.

Following the separation, Robert and his mother returned to Pennsylvania. They lived with his maternal grandparents in Whitehall, a suburb of Pittsburgh. His grandparents played a significant role in raising him because his mother faced health problems. Robert attended Baldwin High School in the Baldwin-Whitehall School District from August 1986 until November 1989. He dropped out before graduating, which limited his career options. After leaving school, he worked as a truck driver.

At 9:45 a.m. on October 27, 2018, three religious services were happening in the Tree of Life synagogue in Pittsburgh. Five minutes later, Robert Bowers entered the building armed with a Colt AR-15 semi-automatic rifle and three Glock .357 SIG handguns. He started shooting, and this continued for about 20 minutes.

The first two victims were two brothers, Cecil and David Rosenthal, who were standing at the main entrance. Bowers then moved downstairs to where members of the New Light congregation were gathering. In the basement, he shot and killed Melvin Wax, the leader of the New Light services, along with two other congregants.

Bowers also encountered Dr. Jerry Rabinowitz of the Dor Hadash congregation while he was trying to help others. After leaving the basement, he went back upstairs to the main service area where about 13 worshippers had gathered. Rabbi Jeffrey Myers helped four of those attendees escape. However, Bowers shot seven of the remaining eight people there and injured the last one.

At around 9:59 a.m., police arrived at the scene. Bowers fired at them as he tried to leave but was forced back inside the building. Tactical teams entered about half an hour later, and Bowers shot at them as well. After being wounded in the exchange, he retreated to a room on the third floor and remained there until about 11:08 a.m. when he crawled out and surrendered to the police.

While receiving medical care, Bowers reportedly expressed his desire for Jews to die, claiming that Jews were committing genocide against "his people." In total, Bowers killed 11 people and injured six, including four police officers.