Larry Welch came to Salem in 1983 and became the District Attorney. Larry set his sights on rich girl Hope Brady, who was currently involved with Bo Brady. When Bo and Hope split up after Doug's heart attack Larry made his move. Larry blackmailed the prostitute Diane Parker, who was pretending to see Bo. He told her if she didn't keep Bo away from Hope he'd expose her to her pimp. Larry and Hope soon became engaged, but on their wedding day Bo rode in on his motorcycle and kidnapped Hope from the wedding. Soon afterwards Larry found Bo and Hope, and he threatened to hurt Bo and the Hortons if she didn't marry him. In 1984 Hope learned evidence that Larry had gone crooked, and exposed him. She then turned her back on him, and as a result Larry began to see Gwen Davies.

In 1985 Megan plotted to kill Hope by electrocuting her in a hot tub at Chris' health club, The Body Connection. Megan's plan backfired when she overheard Larry Welch talking to a Russian contact about the 3 prism's Larry's father had invented, which Stefano was after. When Larry found Megan spying on him they got into a fight, and Larry ended up killing Megan. Larry dumped her body in a hot tub, and Megan was found by Hope, who became the prime suspect in her murder. Larry was also blackmailing Alex Marshall and Linda Anderson, because he knew they set fire to Anderson Manufacturing to collect on the insurance money. Later when Larry's girlfriend Gwen Davies heard Larry confessing to Megan's murder in his sleep he tried to poison Gwen. Gwen survived the attempt on her life, and quickly left town after she was well. In 1985 Victor Kiriakis learned that Larry Welch had killed Megan Hathaway, and he used the information to force Larry to take the fall for the crime syndicate Victor was running.

Larry returned to the Salem scene in 2002 when he kidnapped Hope Williams Brady in an attempt to get his revenge for her leaving him, and wanted his revenge on Bo and Victor as well. He was presumed dead after a prison break, but in reality, was helping Nicole in her plans to murder Victor Kiriakis. Unfortunately for Larry, it was only a matter of time before his death was no longer pretend.