Under the sentence announced Thursday, 65-year-old Edward Ates won't be eligible for parole for more than 66 years.
A jury last month convicted Ates of shooting and killing Paul Duncsak in Duncsak's home in Ramsey.
Ates was 62 years old and 285 pounds when Duncsak was killed in 2006.
During the six-week trial, his defense rested on claims that he was too fat to have run up and down stairs to shoot Duncsak, then escape by driving more than 20 hours to his mother's home in Louisiana.
Ates' attorney plans to appeal.
The victim and Ates' daughter were divorced and involved in a bitter custody dispute.