Recently unsealed court documents shed more light on the mindset and actions of the man accused of shooting two Minnesota lawmakers and their spouses.

The suspect accused of fatally shooting a Minnesota lawmaker and her husband in a gun rampage last week was a doomsday "prepper", according to the FBI. The wife of the accused, Vance Boelter, told investigators the family was among a small group of Americans who "prepare for major or catastrophic incidents", said a court document.

Vance Boelter was captured in a wooded area on Sunday night, and charged in the shootings of two state lawmakers and their spouses. He appeared in federal court after being charged with murder.