MONTPELIER, Vt. (AP) — A man pleaded not guilty Thursday to charges he sprayed liquid manure on a marked U.S. Customs and Border Protection car after confronting an agent about why he wasn't doing more to arrest people in the country illegally.

Mark Johnson, 53, of Alburgh, entered the plea in Vermont Superior Court in North Hero to state charges of disorderly conduct and simple assault of a law enforcement officer with fluids. He declined to comment afterward.

Johnson told The Associated Press on Wednesday that his livelihood was hurt by people working on Vermont farms who could be in the country illegally. He said he asked the agent why he wasn't doing more to arrest people working in the U.S. illegally.

Customs and Border Protection says the job of the border patrol is to keep people from entering the country illegally. U.S. Immigration and Customs Enforcement is responsible for enforcing immigration law inside the country.

Johnson, who has a long history of minor brushes with the law, said he didn't know the car was nearby when he turned on his manure spreader.

Border Patrol agent Robert Rocheleau said in an affidavit that Johnson sprayed his car after a profanity-laced tirade Aug. 3 in Alburgh, just south of the Canadian border, in which Johnson complained the border patrol wasn't doing enough to combat illegal immigration.

At one point, Johnson "wrapped his arms around himself and yelled 'Everyone is squeezing me to ... death,'" Rocheleau's affidavit said.

Rocheleau said he expressed sympathy to Johnson and tried to get out of his way.

Johnson then got back into his tractor. At first, a "wave of manure" missed the car by a couple of feet, the affidavit said.

"While passing by my vehicle Mr. Johnson then engaged the PTO shaft to his trailer and covered my vehicle in cow manure," the affidavit said.

Rocheleau drove to a nearby port of entry where he took photographs of his car and reported the incident to his supervisor. He then washed his car and reported what had happened to the Grand Isle County sheriff's department, he said.