MINNEAPOLIS (WCCO) – An 18-year-old Grand Rapids, Minn., man is accused of choking his ex-girlfriend and kidnapping her and their 3-month-old son.

The man also held a knife to a friend’s throat and threatened to kill her and her family, police say.

Rodney Jacob LaBrosse was charged Monday in Itasca County with four felony counts of kidnapping, domestic assault by strangulation and fleeing police.

On July 24, LaBrosse broke his probation by leaving the Alternative Learning Center, after he decided he wanted to visit his ex-girlfriend at her home.

He then had a friend drive him to the Swan Lake Truck Stop and purchase a folding knife for him, according to the criminal complaint.

After driving away from the truck stop, LaBrosse opened the knife, held it against the friend’s throat and told her to drive him to his ex-girlfriend’s home, she told police.

LaBrosse hid in the woods while the friend picked up his ex-girlfriend and infant son in her rental truck.

Then LaBrosse got into the back seat of the truck, locked the doors and put his ex-girlfriend in a choke-hold, the friend told police.

Police found “marks on her neck consistent with strangulation,” according to the criminal complaint.

His ex-girlfriend was able to call her father on her cell phone and scream, “Help!” according to the complaint.

LaBrosse let his ex-girlfriend and son out of the truck at the Swan Lake Public Water Access. The friend left the truck at a home nearby.

Police arrested LaBrosse on Highway 65 after a four to five mile chase.

He told investigators that he wanted to talk to his girlfriend “about being a good parent” and that he had his friend buy him the knife “because it looked cool.”

He faces up to 20 years behind bars and a $35,000 fine.