MCKINNEY, Texas (CBSDFW.COM) – A grand jury will decide if the mayor of Prosper should face charges for leaving the scene of an accident last week.

The crash left a motorcyclist critically injured, and the family said they want justice.

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“Why didn’t anyone else stop, and where was the person that hit him?” asked witness Serena Ashcroft

Ashcroft said drove up on a dark object in the middle of westbound US Highway 380 in McKinney last Monday evening. She quickly realized it was a motorcycle – with its critically injured driver, 72-year-old Rod Carver, lying next to it.

“He had a traumatic head injury, and he was not moving at all, but he was breathing, thank goodness,” Ashcroft said.

While she and other bystanders helped him, she wondered how he could have been left in the street for dead.

Police now say that he collided with a truck driven by Prosper Mayor Ray Smith. Smith, they say, slammed on his brakes to avoid a driver who turned in front of him. And while that driver was at fault, they say, Mayor Smith broke the law by not stopping to render aid.

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“Literally, anybody could have hit him again,” Ashcroft said. “If anybody came upon him, they would have hit him again, and that would have been it.”

Carver’s wife said they’re still waiting on results of an MRI. She says her husband is in critical but stable condition and that his vitals are steady.

Mayor Smith told police that he saw nothing in his rearview mirror and thought he had been hit by a vehicle that drove away.

Barbara Carver says she wants him to admit what he did, and witness Ashcroft casts doubt on his ignorance.

“It’s a heavy motorcycle,” she said. “There was damage to the motorcycle. There were parts laying around. To me, it’s unconscionable, unfathomable that you could not know.”

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CBS 11 reached out to Mayor Smith for comment but never received a response. A Town of Prosper spokesperson said they are aware of the incident but could not comment on it.