When his cyborg experiments combined with necrotic tissue didn't go as well as he planned, D.A. Sinclair decided to kidnap fellow college student, Rick Sheridan. D.A.'s plans might have proved fruitful had Rick not been the dorm-mate of the superhero, Invincible. Invincible encountered the first zombie-cyborg Reanimen, but couldn't figure out where they were coming from. It wasn't until, D.A. Sinclair kidnapped Rick, that Invincible was able to track him down and put an end to his madness. Rick was returned to a fairly normal state by the Global Defense Agency that Invincible works with.
Major Story Arcs
Global Defense Agency
Cecil Stedman, head of the GDA, saw potential in Sinclair's Reanimen however, and so he was recruited by the GDA to put his skills to use for the greater good. Sinclair has since reformed, and the government now has access to its own army of Reanimen, made from soldiers who died in the line of duty.
Following the fall out of the Invincible War, where Angstrom Levy attacked the world with countless evil versions of Invincible, the GDA even went on to make Reanimen out of the countless dead Invincibles.