Vance Luther Boelter, suspect in the shootings, left behind a letter addressed to the FBI director, prosecutors said.

U.S. House members are able to pay for security using funding from what’s known as the Members’ Representational Allowance (MRA). As of 2016, House members had access to as much as $1.8 million in MRA funding, which they have significant discretion over.

The man sought by authorities for allegedly shooting Democratic lawmakers in Minnesota on Saturday worked for a security company that advertised a fleet of ‘police type vehicles.’

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.

A massive search is underway for a 57-year-old Minnesota man accused of fatally shooting Democratic lawmaker Melissa Hortman and her husband and injuring a second Democratic lawmaker and his wife in separate “politically motivated” shootings, authorities said.

Minnesota lawmaker Melissa Hortman, a Democrat, was killed by a gunman impersonating a police officer; Democratic state senator John Hoffman and his wife were also shot.

Vance Boelter was arrested Sunday night in a field, officials said, ending a massive search that put the entire state on edge for nearly two days.