WICHITA, Kan. (AP) — A Wichita man has been sentenced to life in prison in the shooting death of his wife.

The Wichita Eagle reports that 32-year-old Derek Campbell must serve 50 years before becoming eligible for parole under the sentence imposed Thursday in Sedgwick County District Court. He was convicted in March of first-degree premeditated murder in the April 2015 killing of Rebecca Campbell.

Prosecutors say he killed her because he wanted out of their marriage and had rekindled a romance with an old girlfriend. Evidence presented at his trial showed he had researched divorce online and browsed dating websites before the deadly shooting.

Campbell maintains the shooting was accidental. He said at the sentencing that he thought the gun was unloaded and that he loved his wife with “all my heart.”