Southampton Town police released the name of the suspect in a hit-and-run that killed a Syosset nun on an evening stroll in Water Mill nearly two weeks ago.
The man, Carlos Armando Ixpec-Chitay, 30, of Riverhead, a Guatemalan national, is still at large, authorities said.
Chitay is accused of driving the car that struck and killed Sister Jacqueline Walsh on July 9, authorities said.
The search for Chitay, who police said fled the state, has led the U.S. marshals' fugitive task force out west, said Lenny DePaul, U.S. marshal chief.
The car driven by Chitay, a 2009 Volkswagen Touareg belonging to his employer Andrew Zaro, was found abandoned with front-end damage about a half-mile from Walsh's body and Zaro's home on Rose Hill Road, where Chitay was a groundskeeper, police said.
Chitay is about 5 feet, 7 inches tall, 140 pounds, with brown eyes and hair, police said.
Anyone with information is asked to call detectives at 631-702-2230 or email crimetips
Southampton police delayed releasing the suspect's name saying it could jeopardize the investigation.
Chitay pleaded guilty in 2007 to operating a vehicle under the influence of drugs or alcohol in Suffolk County, records show.