Stillwater County fired its weed district coordinator on Oct. 21 amid an investigation into the use of county equipment on a county commissioner's land.

A week later, William Patterson was served an arrest warrant and charged with felony theft in Cascade County, where he's accused of stealing public property after being fired there.

Stillwater County Attorney Nancy Rohde outlined Patterson's firing in a press release.

"The criminal investigation, though it remains ongoing, yielded sufficient evidence to show that in fact Patterson did utilize county equipment to include the spray truck, Kubota side-by-side ATV and the Polaris four-wheeler along with chemicals both inside and outside of Stillwater County on private property for his personal weed spraying business creating cause for termination, effective immediately," she said.

Patterson started work with the county in February 2015. He'd been on leave since June as the Montana Division of Criminal Investigation looked into the case. He was accused of using the county equipment to spray land belonging to Dennis Shupak, a Stillwater County commissioner.

Shupak did not return a request for comment.

By July, Rohde said there was "substantially more" to the case, including that pornography was found on Patterson's county computer.

John Barnes, a spokesman for the Montana Department of Justice, confirmed that the investigation is ongoing.

On Thursday, Stillwater County deputies served an arrest warrant on Patterson on Cascade County charges, as first reported by the Stillwater County News. Sheriff Cliff Brophy confirmed the arrest Monday.

Patterson made his initial court appearance Friday after he had posted a $1,000 bond, according to Cascade County court records.

Patterson faces a felony theft charge stemming back to 2014. He was a supervisor for the weed and mosquito district in the north-central county.

He was fired in October 2014, court documents state. Soon after, Cascade County Public Works Director Brian Clifton reported missing items from the department. One of the items, an air tank, was kept in Patterson's van to refill a leaky tire, charges state.

Other missing items included six tires and the front grille of a truck.

Deputies from the Cascade County Sheriff's Office went to Patterson's home and found the grille and tires on Patterson's truck, charges state. Patterson had no explanation for where he got the items.

Reached on Monday, Patterson gave a reporter no comment.