An off-duty St. Croix County Sheriff's Office K-9 officer was formally charged earlier this week with possession of a firearm while intoxicated following a December traffic stop outside New Richmond.

Wisconsin State Patrol located a loaded handgun inside John Shilts Jr.'s vehicle, according to a criminal complaint filed in St. Croix County Circuit Court.

The seven-year veteran of the department was arrested on suspicion of drunken driving after his vehicle allegedly almost struck a St. Croix County deputy's patrol vehicle shortly after 11 p.m. Dec. 30, 2018, on County Road A, forcing the deputy to swerve into a ditch to avoid a collision.

The deputy, who caught up to Shilts and initiated the stop, told Wisconsin State Patrol he thought his "life was passing in front of" his eyes, according to the state trooper's report.

The criminal complaint gave the first detailed account of the traffic stop, which included allegations that Shilts told state patrol it was another vehicle - not his - that almost hit the deputy, that he refused a preliminary breath test and part of the field sobriety test.

Wisconsin State Patrol was called to handle the traffic stop to eliminate any conflict of interest.

According to the complaint:

State patrol arrived on scene of the traffic stop at approximately 12:15 a.m., Dec. 31, 2018, and found Shilts on the driver's side of his vehicle. The trooper noted Shilts was "argumentative" throughout the process.

Shilts told the trooper he had one drink per hour and started drinking around 5 p.m., but when asked what time he stopped drinking, he said he didn't want to answer any more questions because he had been detained for a long time.

When asked again, Shilts interrupted and said, "Let's do the fields and I'll get going and get over it."

The trooper put Shilts through the field sobriety test, but refused to count down from 64 to 49 and when asked to take a breath test, he said, "I'm not doing it because I passed fields."

Shilts was arrested at 12:39 a.m. and placed in the trooper's squad car.

The trooper went to Shilts’ vehicle to retrieve his wallet and phone and saw a loaded, holstered handgun and handcuffs inside the driver’s door. Sheriff Scott Knudson confirmed in an email to RiverTown that the weapon was not a department-issued firearm.

En route to the hospital for a blood test, Shilts argued that he had passed the field sobriety tests and so there was no probable cause for an arrest, before failing to answer whether he consented to a blood test.

Shilts also was cited for a seat belt violation, operating left of center and speeding (30-34 mph over limit) as a result of the OWI incident. He had pleaded not guilty to all forfeiture-level charges. His initial appearance in court is Feb. 6.

Following the arrest, Shilts was placed on paid administrative leave pending an internal investigation, according to Sheriff Scott Knudson.

Shilts is the son of Knudson's predecessor in office, John Shilts.