In 1962, Huberty enrolled at a Jesuit community college, where he earned a degree in sociology. He would later receive a license for embalming at the Pittsburgh Institute of Mortuary Science in Pittsburgh, Pennsylvania.
While at Mortuary School, he met his wife Etna, whom he married in 1965 and had two daughters – Zelia and Cassandra. The Huberty family settled in Massillon, Ohio, where James worked as an undertaker at the Don Williams Funeral Home. In 1971, the Huberty family was forced to relocate to Canton, after their house in Massillon was set ablaze.
While living in Canton, Huberty found work as a welder for Union Metal Inc. Huberty and his wife Etna had a history of violent behavior. At a birthday party for a neighbor's daughter, Etna instructed her daughter Zelia to physically assault one of her classmates. In a related altercation with the child's mother, Etna threatened the woman with a 9 mm pistol; although she was arrested, the Canton police failed to confiscate the weapon. At one point James shot his German Shepherd in the head when a neighbor complained about the dog damaging his car.
As a result of a motorcycle accident, Huberty had an uncontrollable twitch in his right arm, a condition that made it impossible to continue as a welder. In January 1984, the Huberty family left Canton and briefly stayed in Tijuana, Mexico before settling in San Ysidro, a community of San Diego, California. He was able to find work as a security guard in San Ysidro, however he was dismissed from this position two weeks before the shooting. His apartment was three blocks away from the site of the massacre.
Prior to the shooting
On the day before the massacre, Huberty had called a mental health center. The receptionist misspelled his name on intake as "Shouberty". Since he had not claimed there was an immediate emergency, his call was not returned. Huberty and his family went to the San Diego Zoo on the morning of July 18, and had eaten at a McDonald's in the Clairemont neighborhood in northern San Diego a few hours prior to the massacre.
Before Huberty left for McDonald's, his wife Etna asked him where he was going. Huberty responded that he was "hunting humans". Earlier that day he had commented to his wife, "Society had its chance."
When questioned by police, Etna gave no explanation as to why she failed to report this bizarre behavior. A witness, who spotted Huberty as he left his apartment and proceeded down San Ysidro Boulevard with two firearms, phoned police, but the dispatcher gave the reporting officers the wrong address.
The massacre began at 3:40 p.m. and lasted for 77 minutes. Huberty had spent 257 rounds of ammunition before he was fatally shot by a SWAT team sniper, Chuck Foster, perched on the roof of the post office adjacent to the restaurant. Initially, law enforcement and emergency crews responded to the McDonald's located at the U.S. International Border with Tijuana at 3:15 p.m., and 15 minutes later changed directions after they learned that the shooting was actually taking place at the McDonald's next to the post office approximately 2 miles away.
Although Huberty stated during the massacre that he had killed thousands in Vietnam, he had never actually served in any military branch. Eye-witnesses stated that he had previously been seen at the Big Bear supermarket and later at the U.S. Post Office. It was surmised that he found the McDonald's a better target.
Due to the number of victims, local funeral homes had to use the San Ysidro Civic Center to hold all the wakes. The local parish, Mount Carmel Church, had to have back-to-back funeral masses to accommodate all the dead.