Authorities say they are continuing to investigate a student murder-suicide this year just off the University of Maryland, College Park campus, a revelation that comes a month after the case was declared closed.

Detectives are not looking for additional suspects but are seeking background information on the alleged shooter, Dayvon Green. They are also awaiting responses to subpoenas in the case, according to a Prince George's County police spokesman.

A department attorney, Jamar Herry, cited the inquiry as a reason not to provide a copy of the case file requested by The Baltimore Sun through the Maryland Public Information Act.

Police would not say who or what was subpoenaed, or what information police are looking to find on Green. The graduate student apparently shot himself in the head after fatally shooting one of his roommates and wounding another.

Police say Green lured two of his off-campus roommates outside of their shared home Feb. 12 by lighting multiple fires in the basement and backyard. He then chased them with a handgun, killing roommate Stephen Rane and wounding roommate Neal Oa before shooting himself, according to police reports.

Rane, a graduate of Centennial High School in Ellicott City, was a senior English major; Oa was a junior economics major; and Green was a graduate student studying engineering who had grown up in the Baltimore area and attended Morgan State University.

Police said last month that they had closed the case, which allowed for the release of autopsy reports for both Green and Rane. Those reports showed Green had been impaired by alcohol at the time of the shootings. The initial investigation had focused in part on Green's reported mental illness.

Most files in closed criminal cases are available through the Public Information Act, while documents in open investigations can often be withheld.

Investigators are not looking for any additional suspects, and the case is closed "from a who-done-it standpoint," but investigators "still had some subpoenas out referencing [Green's] background," said Lt. William Alexander, a police spokesman.

The only document that was released to The Sun under the public information request was a four-page "incident report" written by first-responding officers.

Much of the information in that report has already been made public, either by the department or through interviews of people with knowledge of the case or those involved. But it does provide further insight into what Oa, the surviving roommate, told officers in the hours following the incident, particularly about the relationships between the roommates prior to the shootings.

Oa "advised that for the last couple of weeks the suspect had been acting very strange," the report says.

"They knew that the suspect had guns inside the residence. His odd behavior began to increase. One of the other residents had even left the residence a week before indicating he was in fear of the suspect's behavior because he knew he had guns in his room," the report reads.

"The residents in the house had spoken to the suspect about his behavior and voiced their concerns about him having guns in the house," it reads. "The suspect advised them that he would not harm anyone there and that if those were his intentions he would have already done it."

—Kevin Rector