1991 Royal Oaks Post Office Shooting

MASS MURDERERS

6/23/20251 min read

On November 14, 1991, a tragic mass shooting occurred at the Royal Oak Post Office in Michigan, resulting in the deaths of four employees and injuries to several others. The perpetrator, 31-year-old former postal worker Thomas McIlvane, ultimately took his own life during the incident.

Thomas McIlvane had a history of disciplinary issues during his tenure with the U.S. Postal Service, leading to his termination in 1990 for insubordination. He contested his dismissal through arbitration, but on November 13, 1991, he was informed that the decision had been upheld against him. Prior to the shooting, McIlvane had made threats of violence, including a voicemail stating, "I'm going to blow everything away... I'll kill you, too."

The following morning, McIlvane entered the Royal Oak Post Office through a rear loading dock armed with a modified .22-caliber Ruger 10/22 semi-automatic rifle. He proceeded to move through the facility, targeting individuals he believed were responsible for his firing. In total, he fired approximately 100 shots, killing four employees and wounding several others before committing suicide.

Victims

Mary Ellen Benincasa, 32: Injury compensation specialist.

Christopher Carlisle, 33: Manager of branch operations.

Keith Ciszewski, 37: Labor relations assistant.

Rose Marie Proos, 33: Postal supervisor.