Montpelier, Vt. — A man found shot to death was the focus of a heroin distribution investigation in the St. Johnsbury area that was being run by the Vermont Drug Task Force, federal court documents say.

The documents filed on Monday in a separate heroin distribution case said that police began an investigation on Saturday into the disappearance of Michael Pimental. His body was found on Sunday by the side of a rural road in Concord, Vt., just off U.S. Route 2.

An autopsy found that Pimental, 37, of Waterford, had been shot multiple times. Police have said his death was drug-related. No one has been charged with killing him.

The court documents that note Pimental’s alleged involvement in a heroin distribution ring were filed to support heroin distribution charges against Krystal Whitcomb, 27, whom police describe as Pimental’s girlfriend, and her father, Shawn Whitcomb, 51.

The Whitcombs appeared in federal court on Monday. They were being held pending a detention hearing on Thursday. Attorneys for them did not return calls on Tuesday seeking comment.

A federal court affidavit filed on Monday by Wade Cochran of the Vermont Drug Task Force said police began the heroin investigation in July involving Pimental and the Whitcombs.

On Sept. 6, a confidential informant bought 20 bags of heroin from Shawn Whitcomb. On Wednesday, police witnessed a confidential informant buying heroin from Krystal Whitcomb, who was driving a silver Cadillac.

The affidavit did not say why police began searching for Pimental on Saturday.

Shawn Whitcomb was arrested on Sunday on drug charges, and he was questioned about what was then considered Pimental’s suspicious death.

On Sunday, a Grafton County, N.H., sheriff’s deputy stopped the Cadillac that Krystal Whitcomb had used in the Oct. 10 drug buy in Haverhill. Krystal Whitcomb was in the passenger seat.

Police found two handguns in the car that Whitcomb said belonged to her.

The driver of the car was not identified, but he was taken into custody by New Hampshire authorities.

Krystal Whitcomb voluntarily traveled back to Vermont with Vermont State Police detectives. After they arrived in Vermont, she was charged with the Oct. 10 heroin sale.