ORONO – Maine State Police were back Monday night at the scene of an early morning shooting that left a 21-year-old college student dead as final exam week began.

Investigators and the medical examiner returned to 14 Water St. to examine more evidence before a cause of death could be determined, according to Stephen McCausland, spokesman for the Maine State Police.

The gun used in the shooting was recovered inside the apartment this morning, he said.

Hannah M. Corbeil, a senior at the University of Maine, was found shot to death in her bedroom when Orono police arrived at the duplex about 3:30 a.m. Monday, said McCausland.

Also in the house at the time of the shooting were Corbeil’s male and female roommates and a male friend of the victim, according to police. None of the three could be reached for comment.

“We have not ruled anything out,” McCausland said Monday afternoon, “including that this may have been self-inflicted. No one has been charged. The two roommates and the third individual have been very cooperative.”

UM spokesman Joe Carr identified the roommates as university students Colin Hopper and Elizabeth Rogan. Corbeil was from East Haddam, Conn., located in south central Connecticut. She was a senior majoring in forestry, said Carr.

The male friend was not identified by police or university officials.

“Hannah was a student who showed great promise,” said David Field, a professor of forestry resources who knew Corbeil. “She will be deeply missed by the faculty, staff and students in our department.”

UM President Peter Hoff issued a similar statement Monday afternoon.

“Hannah’s death is a tragic loss,” he said. “We extend our deepest sympathies to her family and friends during this very difficult time.”

Corbeil is the third UM student in 13 months whose death has been investigated by police.

The Oct. 23 death of an 18-year-old freshman from Windsor was ruled a suicide. Students walking on a path that leads from Hilltop Road to school wildlife pens and University Forest found the man shot to death.

A junior participating in an exchange program from the University of Wisconsin-Eau Claire plunged to her death from her fourth-floor dorm room Nov. 17, 1999. Her death also was ruled a suicide.

Carr said that members of the university community who want to talk with a counselor about Corbeil’s death may contact the UMaine Counseling Center at 581-1392. Clergy are also available at the Newman Center at 866-2155 and the Wilson Center at 866-4227.