A New York City woman who was killed while running near her mother's Massachusetts home may have injured her attacker as she was fighting for her life, authorities said Thursday.

Worcester County District Attorney Joseph Early Jr. said the male assailant likely suffered scratches while struggling with Vanessa Marcotte, a 27-year-old Google account manager.

“We believe that there was a struggle between Vanessa and her killer that may have resulted in her killer receiving injuries, and her assailant, we know, was a man,” Early told a press conference. “These injuries, specifically, were scratches, scrapes and/or bruises.”

Early added that investigators have refined the timeline of Marcotte's death to between 1 and 3 p.m. on Sunday, and are asking the public to contact authorities if they noticed any vehicles parked on a nearby road during that time.

Marcotte was found dead Sunday night hours after she went for a run near her mother's home in Princeton, a rural town west of Boston. A law enforcement source told Fox 25 that investigators are examining the possibility that Marcotte was sexually assaulted and then set on fire.

A restaurant in Princeton was at one point an area of interest for investigations, Fox 25 reported.

A manager at the Mountain Barn restaurant, located near a cell phone tower, told the television station that Massachusetts State Police detectives came to the restaurant Sunday evening to question employees.

On Thursday, investigators focused on an area a half mile south of the woods where Marcotte's body was found.

Police told Fox 25 they have received at least 250 tips from the public. Anyone with information is asked to call the Vanessa Marcotte tip line at (508) 453-7589.

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The Associated Press contributed to this report.