On a quiet Father's Day morning, June 16, 1991, a deadly chain of events began to unfold within the United Bank Tower in Denver, Colorado. William McCullum Jr., a 33-year-old male security guard, was on duty, unaware of the violence that was about to disrupt the morning's calm. An armed man, using a false identity, gained access to a secure area of the bank by requesting entry via a freight elevator.
McCullum was the guard who responded to the call and rode the elevator up, where he was ambushed. He was the first of four guards to be killed that day in what would become known as the Father's Day Bank Massacre.
The gunman, having neutralized McCullum, took his electronic pass card and keys to navigate the secure passages of the bank. The assailant's movements through the building were precise, suggesting an insider's knowledge of the layout and security protocols. After killing McCullum, the robber hid his body in a storage room and proceeded to the bank's basement level, where the vault and guard station were located. The perpetrator then systematically murdered three other security guards: Phillip Mankoff, Scott McCarthy, and Todd Wilson, before making off with an estimated $200,000 from the cash vault.
The investigation into the brutal heist led authorities to a primary suspect, James W. King, a retired Denver police officer who had previously worked as a guard at the same bank. On July 4, 1991, King was arrested and charged with four counts of murder. The ensuing trial garnered national attention and was broadcast on television. However, the case against King was largely circumstantial. No direct physical evidence linked him to the crime, and the stolen money was never recovered.
After nine days of deliberation, the jury acquitted James King of all charges. In the years following the trial, he lived a reclusive life and died in 2013. To this day, no one else has been arrested or charged in connection with the Father's Day Bank Massacre. The murders of William McCullum Jr. and his three colleagues remain officially unsolved, a cold case that continues to be one of Denver's most infamous and perplexing crimes.
