COLUMBIA, Mo. -

A congressional investigation of the Truman Memorial Veterans' Hospital is underway after a 78-year-old man was beaten to death in 2013 at the facility.

In a letter dated Jan. 15 and addressed to the secretary of the U.S. Department of Veterans Affairs, Rep. Mike Coffman (R-Colo.) requested a copy of the incident report detailing how the facility responded to the assault and death of Robert Hill on Feb. 1, 2013.

Coffman, a native of Fort Leonard Wood, Mo., is the chairman of the Subcommittee on Oversights and Investigations for the House Committee on Veterans' Affairs.

According to authorities, Rudy Perez Jr. killed Hill at the hospital. Hill was a patient and Perez was there on a 96-hour involuntary commitment after an alleged assault on his father. Perez pleaded not guilty by reason of insanity and is at Fulton State Hospital.

The subcommittee has also requested information on any administrative actions against staff or VA officials in connection with the death.

"I am particularly concerned about reports that Mr. Perez first threatened to attack Mr. Hill, he then did attack Mr. Hill, the two were separated, and then Mr. Perez was returned to the same unit as Mr. Hill where the final attack occurred that cost Mr. Hill his life," Rep. Coffman wrote in the letter.

ABC 17 News reached out to Coffman's office, Truman VA Hospital administrators and Congresswoman Vicky Hartzler's office Wednesday.

A spokesman for the Truman VA Hospital in Columbia was not aware of the request for documents Wednesday afternoon, but deferred comment to the national office.

The office of Congresswoman Vicky Hartzler (R - 4) issued the following statement to ABC 17 News late Wednesday night:

"During her recent visit to the Truman VA Medical Center, Congresswoman Hartzler heard from administrators regarding the tragic events of last February and efforts to address security concerns. Like Congressman Coffman, she awaits General Shineseki's response."

There is no word on when the subcommittee will get those documents or when the investigation will be completed.