Death Man makes a big splash in his debut story in Batman 180 (May 1966), by Kanigher, Moldoff and Giella.
The costume does not look as good as it does on the cover, but the thief does live up to his name. His gang is not as impressive, falling quickly to Batman and Robin.
Batman hauls Death Man into court. The villain seems remarkably unconcerned, and then promptly drops dead during his arraignment.
Despite having died, Death Man comes back again, doing his best to kill Batman and Robin. But once again, hen they triumph over him, Death Man drops dead.
Batman does not believe Death Man is really dead, and they go to his grave, and find out tha,t yup, he’s alive again. Death Man has learned how to stop and start his own heart. Death Man gets hit by lightning, and this time Batman believes that he is really dead.
And he sure seems to be, not returning for over thirty years, until Grant Morrison revives him.