Police said Julie Oursler, 28, of Baseline Road, was walking west on Whitehaven Road - in the middle of the eastbound lane - near Stoney Point Road at 3:35 a.m. when she was hit by an eastbound pickup truck driven by Robert Brennan, 70, who lives on Whitehaven Road.

Oursler was struck in her midsection by the truck's rear-view mirror and fell facedown in the roadway, said Gallivan.

Erie County Sheriff's Department authorities said Brennan, who had been driving home, continued driving into his driveway about 60 yards away from the accident and called 911 to report striking the woman. Gallivan said the man believed it was "the best way to help her" at the time.

Moments later, Brennan came out of his home to assist Oursler and saw Deputy David Makowski in his police cruiser run over Oursler with his right tire, deputies said. The Erie County medical examiner pronounced her dead at the scene.

"We have not yet determined which accident caused her death," Gallivan said Monday at a news conference at the Erie County sheriff's office.

Police said the woman was wearing a black Halloween outfit and the road was dark and unlit at the time of the accident. Officials said no charges are expected against Brennan or Makowski.

About three hours earlier, police said, Oursler was involved in an altercation with a woman inside the Island Lanes bowling alley at 1887 Whitehaven Road during an annual Halloween party.

The confrontation erupted into a physical fight in the parking lot involving Oursler's husband, Christopher, and one or two other men, said Gallivan. During the fight, Christopher Oursler received minor scrapes and a cut above his eye and was later treated in DeGraff Memorial Hospital in North Tonawanda and released.

"We're trying to piece together the incident to find out who engaged in criminal conduct," said Gallivan.

Makowski, who had been dispatched to the bowling alley with Deputy John McCarthy, found Oursler to be under the influence of alcohol and "unable to drive her car," so he drove her to her mother's house on Meadow Lane, Gallivan told the media.

About two hours later, when her mother realized Oursler had walked away from the home, she followed her in her car but was unable to persuade her to get inside.

The mother then called Grand Island Fire Company at about 3:30 a.m., reporting that Oursler was walking to the sheriff's Grand Island substation looking for her husband, who she thought had been arrested.

About five minutes later, Oursler was struck by the vehicles.

An autopsy performed Monday showed Oursler died of multiple injuries. Toxicology results are expected in about five weeks.