WATERBURY, Conn. — Waterbury police have obtained an arrest warrant for a man they say fatally stabbed his 85-year-old neighbor.

Police say 22-year-old Ervis Mecollari is linked to Laura Orso’s death by evidence at the scene, and that he will be charged with murder when he is found.

Mecollari was a downstairs neighbor of Orso, an 80-pound widow who was stabbed 37 times in her Waterbury apartment on Dec. 20, 2008.

Police say Mecollari bought a bus ticket to Florida shortly afterward, but got off in New York City and has not been seen since.

Detectives have traveled more than 4,000 miles to Albania in search of Mecollari, an Albanian immigrant, but have not located him.

A $15,000 reward has been posted for information.