A grand jury will have to weigh whether it was reckless shooting or a tragic accident that cost a woman her life when it decides whether to bring criminal charges against a western New York hunter who shot and killed a neighbor he said he mistook for a deer, investigators said Tuesday.

Rosemary Billquist, a 43-year-old hospital worker, hospice volunteer and marathoner, was killed Thanksgiving eve while walking her two yellow Labradors, Stella and Sugar, behind her home in the town of Sherman about 5:30 p.m., under an already dark early evening sky.

Hunter Thomas Jadlowski told police he fired a single round from his hunting pistol at what he thought was a deer the length of two football fields away. He heard Billquist cry out, ran to her and called 911. Jadlowski was applying pressure to Billquist's wound when first responders arrived in the field.

Billquist's husband, Jamie Billquist, told reporters he was inside his house when the barking of his dogs, who had come home on their own, stirred the first signs of dread.

He rode with his wife in an ambulance to a hospital 30 miles (48 kilometers) away in Erie, Pennsylvania, where she died.

"She was like an angel," Jamie Billquist told WIVB-TV. "She would help anybody and do anything you know for anybody before she would do anything for herself."

The rifle hunting season was not yet a week old when investigators from the state Department of Environmental Conservation and Chautauqua County Sheriff began investigating the death. One key factor is timing, since the shooting happened about 40 minutes after sunset.

It is illegal to hunt big game after sunset or before dawn in New York state.

Chautauqua County District Attorney Patrick Swanson said his office would ask a grand jury to consider charges of criminally negligent homicide or reckless conduct that resulted in Billquist's death. Either felony charge could result in several years in prison.

"Two lives were lost at that moment," Sheriff Joseph Gerace said.

Jadlowski could not be reached for comment Tuesday. A telephone listing was not in service.

The sheriff said it is not uncommon, nor illegal, for hunters to use the type of higher-power pistol Jadlowski had. Some of the weapons are holdovers from before rifle hunting of deer and bear became legal in the county in 2011, he said. He described the gun as "like a rifle without a stock."

While noting the majority of hunters are responsible, Gerace said he and neighboring counties in the rural westernmost corner of the state see their share of hunting incidents.

Two days after Billquist's death, Gerace's office charged an Ohio man with reckless endangerment for opening fire on a brown pick-up truck he believed was a deer. One round from a high-powered rifle struck the truck but missed its two occupants.

"Occasionally we have people use horrible judgment and negligence and it ends up in tragedy," the sheriff said.

In the days since Billquist's death, her husband and others have recalled acts of kindness they said were typical, recounting for reporters how she brought pets to hospice patients and placed a bench outside a local hospital where she worked after seeing a man laboring to stand. She stenciled on it: "In a world where you can be anything, be kind."

A funeral was scheduled for Wednesday at Sherman Community Church, following a wake Tuesday.

At a vigil on Thanksgiving, dozens of neighbors left their homes to sing "Amazing Grace" at a vigil.

"She could've really made a difference in a lot more people's lives," Jamie Billquist said. "In just the short time she was here, obviously she touched a lot of lives."