Mark Orrin Barton (April 2, 1955 – July 29, 1999) was a spree killer from Stockbridge, Georgia, who, on July 29, 1999, killed 12 people and injured 13 more. The shootings occurred at two Atlanta day trading firms, Momentum Securities and the All-Tech Investment Group. It is believed that Barton, a daytrader, was motivated by US$105,000 in losses over the previous two months. Four hours after the Atlanta shootings, Barton committed suicide at a gas station in Acworth, Georgia. He had been spotted by police and was ordered to stop, but shot and killed himself before the police could reach him.Following the shootings, police searching Barton's home found that his second wife, Leigh Ann Vandiver Barton, and two children, Matthew David Barton (12) and Mychelle Elizabeth Barton (10), had been murdered by hammer blows before the shooting spree. The children had then been placed in bed, as if sleeping. According to a note Barton left at the scene, his wife was killed July 27 and the children murdered July 28.Prior to the massacre, Barton had been a suspect in the 1993 beating deaths of his first wife, Debra Spivey, and her mother, Eloise Spivey, in Cherokee County, Alabama. Although he was never charged in either of the crimes—and though the note he left with the bodies of his children and his second wife denied any involvement in the 1993 murders—he is still considered a suspect in those murders by authorities.