U.S. authorities in Minnesota on Sunday captured the suspect accused of killing a Democratic state lawmaker and her husband, bringing a two-day manhunt to an end.

The suspect, 57-year-old Vance Boelter, allegedly disguised himself as a police officer, then shot and killed Democratic state representative Melissa Hortman and her husband Mark at their home early Saturday.

Boelter was captured in Sibley County, a rural area about an hour southwest of the Minneapolis suburbs where the murders had occurred, police and state officials said.

"After (a) two-day manhunt, two sleepless nights, law enforcement have apprehended Vance Boelter," Minnesota Governor Tim Walz told a late-night news conference.

Police described the search as the "largest manhunt in (the state's) history", with 20 SWAT teams and several agencies working to find him.