The man who became the master assassin called Deadline started of as a small time hitman for one of America's organized crime families. While details of his upbringing and career are sketchy, his uncanny aim has always made him a formidable foe.

When the alien Dominators unleashed a genebomb over Earth, the hitman who would become Deadline was a casualty, having his metagene activated. At first he grew extremely ill and thought he would die from the accident. Instead, he recovered and found that his body had bulked up and his skills and reflexes had dramatically improved. His skin became extremely dense making him impervious to pain.Topping off these powers was his ability to phase himself or any object he touched through solid materials.

Outfitting himself with high-tech gear and calling himself Deadline, he endeavored toestablish himself as America's premier assassin.

He clashed with Starman (Will Payton) early in his career in Las Vegas, causing a great deal of damage to the Las Vegas strip and suffered a radiation burn on his left hand due to this battle with Starman. This fuels Deadline's hatred for Starman and leads them to clash many times after.

Much later Deadline is vacationing in Bialya after it is opened up to supervillains. When the country is assaulted by the Justice League, Deadline is captured by Green Lantern Guy Gardner. Deadline then becomes a member of a more villainous version of the Suicide Squad, propping up the dictatorship in the Bermuda Triangle island of Diabloverde. His team is shown terrorizing civilians for fun. Amanda Waller and her Squad take out him and his colleagues while attempting to remove the dictator.

During "Underworld Unleashed", Deadline meets fellow mercenaries Deadshot, Bolt, Merlyn, and Chiller, and forms the Killer Elite, a supergroup of assassins. He is then hired by King Theisley of Poseidonis to assassinate Aquaman, during the battle he manages to get Aquaman out of the ocean and into the sky, where Deadline has the advantage.But still he fails to kill him. He is also hired to kill Steel at one point but fails that as well.

While attempting to escape from Iron Heights with cohorts Deadshot and Merlyn, Deadline is shot and apparently killed by Warden Wolfe. But because he was Jokerized at the time the chemical had healing properties and Deadline slowly recovered, only to be gravely injured once again when he and several other assassins stupidly went gunning for his former Killer Elite teammate Deadshot.