SLIPPERY ROCK — A Butler man on Wednesday was ordered to stand trial on vehicular homicide and other charges at a preliminary hearing that in part hinged on more than year-old weather reports.

District Judge William O’Donnell ruled that prosecutors had sufficient evidence to bring Zachary E. Sawyer, 33, to trial in connection with a deadly crash last year in Muddy Creek Township

State police allege Sawyer was criminally negligent July 28, 2015, when at dusk he drove his 1969 Oliver farm tractor onto Route 19.

Between twilight and the dark of night, Earl A. Tindall’s 2007 Jeep Liberty slammed into the back of the antique tractor, which had no working taillights, investigators said.

Tindall, 76, of Perry Township, Lawrence County, who apparently did not see the slow-moving tractor until it was too late, died of injuries in the wreck.

Police in May, nearly 10 months after the crash, filed their criminal case against Sawyer, charging him with homicide by vehicle, a felony, and involuntary manslaughter and reckless endangerment, both misdemeanors.

Trooper Shawn Palmer testified at Wednesday’s hearing that moments before the fatal wreck, the defendant’s tractor and the victim’s Jeep were both traveling south just north of Portersville.

The tractor was going 20 mph on the road, which is a 55 mph zone, and it did not have hazard flashing lights on.

Palmer, who was dispatched to the crash at 8:55 p.m., said that Sawyer had driven from a farm in Stoneboro to Muddy Creek Township.

Tindall eventually traveled up to the tractor but left no skid marks to indicate he tried to brake before the rear-end collision.

The collision forced the tractor off the road and into a utility pole. The Jeep also went off the road and stopped in a yard.

Tindall was taken to Jameson Hospital in New Castle where he was pronounced dead, authorities said. He was not wearing a seat belt.

Sawyer was taken to Butler Memorial Hospital with less than serious injuries.

“He was banged up, but I wouldn’t say they were too severe,” Palmer told Sawyer’s attorney, Michael Jewart, during cross-examination. “He was lucky.”

The trooper acknowledged that the tractor had a large, orange fluorescent emblem on it but its rear taillights were “not connected to a power source and were incapable of emitting light.”

Police noted that when they asked Sawyer if he had his lights on the tractor, according to court documents said, he replied that he “did not believe it was dark enough to have them on.”

During his testimony, Palmer referred to Weather Channel reports that showed sunset that day was 8:39 p.m., which preceded the crash by minutes.

“Would it have been dark by then or just dusk,” prosecutor Russ Karl, a county assistant district attorney, asked the trooper.

“I believe it’s called nautical twilight,” Palmer replied, “just dark enough where lighting would be required. It was after sunset.”

During his questioning, Jewart asked the officer how witnesses described how dark or not so dark it was.

By most or all accounts, Palmer said, they told him it was dusk but still light out.

At the end of the hearing, Jewart asked O’Donnell to dismiss the most serious charges, arguing that Palmer’s testimony offered “no indication of the need for lighting (on the tractor) at the time (of the crash).”

He also noted that the wreck happened near Eppinger’s convenience store where there would have been additional ambient lighting.

Jewart claimed the prosecution had not proven that his client’s action rose to the level of gross negligence or recklessness, the legal elements of vehicular homicide and involuntary manslaughter.

However, Karl countered that he had met his burden, referring to the tractor that had no working rear lights while on the road after sunset, and to Sawyer’s decision not to pull off the road when he saw Tindall’s head lights coming up from behind.

Sawyer remains free on $35,000 unsecured bail.

Karl and Jewart both declined to comment following the hearing.