Story highlights Home invasion occurs in Uniondale, New York

Hofstra junior lived with her twin, other students

Andrea Rebello was killed, along with suspect

A 21-year-old Hofstra University junior was fatally shot early Friday in an exchange of gunfire between a suspected home invader and police who came to the house, officials said.

Andrea Rebello lived with her twin sister in an off-campus house in Uniondale, New York. A male suspect wearing a black ski mask forced his way into the residence, which the sisters shared with two other students, according to police.

At some point during the night, the twins' female roommate was able to leave the home and call police, a Nassau County police spokesman told CNN on Friday.

When police arrived, there was an exchange of gunfire that left Andrea and the suspect dead. Police say the source of the gunfire that killed Rebello is still under investigation.

It was not immediately known whether the suspect knew the students. Armed robbery was believed to be the motive for the home invasion.

Andrea's high school principal, Carol Conklin-Spillane, said the girls' home community in Westchester, New York, was heartbroken.

She described Andrea as a fun-loving, personable and self-aware young woman. The sisters were a perfectly complemented "match set."

"There are twins who are just siblings and there are twins who are close, and then there was Andrea and Jessica," she said. "They were best friends by choice."

Conklin-Spillane said while on her way to Sleepy Hollow High School in New York she heard a student had been killed.

"I remember saying to myself that some mother's heart will be broken today," she said. "Never did I imagine it could be one of our community members."

Andrea's parents, Fernando and Nella Rebello, are closely tied to the Portuguese community, and always worked to create opportunities for their children, Conklin-Spillane said. The family was extremely close, she said.

Friday was the last day of finals at Hofstra University, right before graduation weekend. The university said in a statement that the commencement ceremonies will go on as scheduled. Andrea Rebello was majoring in public relations.