Charges: Man hit ex-girlfriend, followed her into gas station bathroom before Chisago Co. kidnapping

Ben Tietz is the suspect in the alleged assault and kidnapping. ( Chisago County Sheriff's Office )

New charges in Chisago County detail the violence prosecutors say that led to a Maplewood, Minnesota man kidnapping his own infant son and leading police on a high-speed chase with the child in the backseat.

Now, Ben Tietz is charged with kidnapping and felony domestic assault for the attack and chase on December 26, which led to a wide-range search across the Twin Cities metro.

According to the charges, on the days leading up to the kidnapping, Tietz had been staying at Grand Casino in Hinckley with the mother of his son, who Tietz was not allowed custody of. The mother told investigators that she and Tietz had been arguing. On the 26th, the on-and-off couple met up so Tietz could get his keys. Tietz also asked for a ride to pick up his van.

But, during the ride, the mother says Tietz forced himself into the driver's seat of the car, pinning the mother against the door until she crawled into the backseat. Tietz  According to the charges, Tietz began arguing with her, swinging a closed pocket knife at her before throwing it into the backseat.

Prosecutors say Tietz kept driving the car, taking it south on I-35 while making stops at a liquor store, a gas station in Stacy, Minnesota and then a Holiday gas station in Wyoming, Minnesota. The mother, who deputies said had visible bruises, scratches, and a raised bump on her forehead, told investigators at the gas station, she gathered her stuff and left the vehicles because Tietz kept hitting her.

She went into the Holiday bathroom to make a call. While in the bathroom, surveillance cameras show Tietz walking into the gas station and following his ex into the bathroom. The mother told deputies that Tietz crawled under the stall door and yelled at her for using her phone until a gas station employee came into the bathroom and told Tietz to get out.

Tietz then walked out of the gas station, got into the mother's car, and took off at a high rate of speed, investigators said. After the mother called 911, deputies and police responded, and were able to locate the vehicle. However, they said they were unable to catch up with him and Tietz got away.

Tietz later dropped off his son at a former babysitter's home in White Bear Lake, who contacted police. Tietz was arrested the following day.