Harry Alexander was a Vietnam War veteran and former drug addict in A Stitch In Crime.
Harry Alexander was a soldier for the United States Of America in the Vietnam War, and once the war was over he developed an addiction to drugs. He visited a veteran's hospital to help him with his problems. There, he met a nurse named Sharon Martin with whom he formed a romantic relationship. However, Sharon left him when she realised that Harry had replaced his reliance on substances with a reliance on her. Harry worked at a petting zoo and it was one day while he was there that Lieutenant Columbo visited him and questioned him on Sharon Martin's murder. The lieutenant noted that Alexander was left-handed when he lit a cigarette for himself. Alexander was attacked by Dr Barry Mayfield, who hid in Harry's apartment and chloroformed him when he came through the front door. Dr Mayfield overdosed Alexander on drugs via an injection into his left arm, which killed him when he regained consciousness and deliriously fell down the stairs. This was all an elaborate plan to implicate Alexander in Sharon Martin's murder, however Columbo saw through this by concluding that Harry Alexander would not have naturally injected himself in his left arm due to being left-handed.
Harry Alexander was played by Jared Martin.