MINNEAPOLIS — The Minnesota Supreme Court on Wednesday affirmed all but one of the guilty verdicts — including the most serious conviction of first-degree murder — against a man who admitted to shooting Mahnomen County Sheriff’s Deputy Christopher Dewey in 2009.

Dewey died about 18 months after he was shot by Thomas Lee Fairbanks, who authorities say fired at Dewey after a night of drinking and then engaged in a standoff with police. At trial, Fairbanks admitted he shot Dewey, but said he was drunk and high so there was no intent.

A jury found Fairbanks, 37, guilty of multiple counts, including first-degree murder of a peace officer and four counts of first-degree assault, stemming from shots fired during the standoff. Fairbanks received a mandatory sentence of life in prison without parole on the murder count.