Steve Deever is Joe Keller's former partner in business. When the play begins, he is in jail for the crime that both he and Joe were originally convicted of, shipping cracked cylinder heads to the military which resulted in the deaths of 21 pilots.
Steve and Joe were tried and both convicted, Joe went to prison, but on appeal, he lied to the court, claiming that he was not in the factory on the day that Steve made the decision to ship the cracked cylinder heads to the military in order to meet the time requirements of the military contract.
Joe Keller claimed that he was home sick with the flu that day and denied that he told Steve to weld over the cracks and ship the parts out. So Steve is made to take the blame for the entire incident of the cracked cylinder heads.
The first real information that the reader gets about Steve Deever is when George, his son, and Anne's brother, arrives at the Keller's home to confront Joe about the fact that his father was framed for the crime and that he is wasting away in jail.
George describes his father this way:
"He's a little man. that's what happens to suckers, you know. it's good I went to him in time, another year there'd be nothing left but his smell." (Miller)