Deputies said they were called shortly before 11 p.m. to a home on East Warm Springs Avenue after a fight was reported.
Brian H. Benfield was threatening to kill someone and had already cut two relatives with a knife, said Michelle Keszey, a Sheriff's Office spokeswoman.
The deputies encountered Benfield while he was chasing one of the victims who was escaping from the home, Keszey said.
"Benfield refused to drop the shotgun, instead raising it and pointing it at one of the deputies," she said. "In response, two deputies fired their service weapons, striking Benfield and stopping the attack."
Benfield was taken to Leesburg Regional Medical Center, where he died.
Investigators said Benfield was released from the Florida Department of Corrections on Monday after having served a 25-year sentence for his involvement in a Lake County homicide and robbery.
The deputies, who were uninjured, were placed on paid administrative leave, which is standard procedure for shootings involving law enforcement officers.
The Florida Department of Law Enforcement is investigating the shooting.