Shawn Nelson

Nelson's brother, Scott, said that he became addicted to methamphetamine in the few years prior to the tank incident. His neighbors complained to authorities of him yelling at his roommate at night. Nelson then began to exhibit unusual behavior. On one occasion, he dug a hole 15 feet (4.6 m) deep in his backyard in an attempt to mine for gold. One of his friends, Carson Honings, referred to the mine shaft as Nelson's "new hobby". In April, he filed two damage claims against the city – for police negligence and false arrest – totaling $2 million.

At dusk, approximately 6:30 p.m. on Wednesday, May 17, 1995, Nelson drove his Chevrolet van to the California Army National Guard Armory on Mesa College Boulevard to the Kearny Mesa neighborhood of San Diego. Employees at the armory were working late and the gate to the vehicle yard, which was completely deserted, was left open.

Nelson's neck and back problems, combined with the theft of plumbing equipment from his truck in June 1994, effectively halted his business. With no income, his utilities were cut off and his house went into foreclosure. In April 1995, Nelson's live-in girlfriend moved out of their shared home.

From the armory, Nelson traveled along neighborhood streets, eventually turning north on Convoy Street, west on to Balboa Avenue (then signed as State Route 274), and entered Interstate 805 heading south. While on I-805, he attempted to knock down a pedestrian bridge by running into the pillars, but failed after a few hits, and decided to continue onto the freeway. Nelson then drove the tank onto the State Route 163 freeway heading southbound, resulting in the freeway being closed and thousands of motorists being stuck. At least one news article speculated that he may have been headed to Sharp Memorial Hospital, which he had unsuccessfully sued in 1990 and partially blamed for his mother's death. After Nelson attempted to cross into the northbound lanes of State Route 163, the tank became caught on the concrete median barrier and lost one track.

Nelson's mother died in 1988 and his father died in 1992; in between, his wife of six years filed for divorce in 1990. That same year, he was hospitalized at Sharp Memorial Hospital for neck and back injuries sustained from a motorcycle accident. Nelson later sued the hospital for $1.6 million, citing negligence, assault, battery, and false imprisonment. A superior court judge dismissed the case, and the hospital counter-sued for $6,640 in medical fees and legal expenses. Nelson claimed that he was forced to be treated without his consent.

Shawn Timothy Nelson (August 21, 1959 – May 17, 1995) was an American plumber and U.S. Army veteran who stole an M60A3 Patton tank from a U.S. National Guard armory in San Diego, California and went on a rampage on May 17, 1995; he destroyed cars, fire hydrants, and an RV before being shot and killed by a policeman.

Shawn Nelson was born in Birdseye, Utah on August 21, 1959, the second of three sons. He grew up in the Clairemont neighborhood of San Diego, California and graduated from Madison High School prior to his enlistment in the United States Army, where he served for two years until his honorable discharge in 1980. After his discharge, he returned to San Diego and worked as a plumber.