MOORHEAD, Minn. (FOX 9) – A man arrested after the body of a missing teenager was found in the Red River in Moorhead, Minnesota, is now charged with her murder.

The order

• Isaac Arthur Arndt, 18, told police he fatally stabbed 14-year-old Jaelyn Walker “approximately 13 times” on the evening of August 19.
• According to police, Arndt admitted to killing the girl. The two had been in a relationship for several months, but it had ended shortly before the stabbing.
• Investigators reportedly found bloody items in Arndt’s apartment.

What we know

Isaac Arthur Arndt, 18, of Fargo, North Dakota, is charged with first-degree murder in the death of 14-year-old Jaelyn Walker, whose body was found in the Red River early Tuesday morning.

According to police, Arndt went to the Clay County Law Enforcement Center shortly after 11 p.m. on Monday, August 19, and reported the incident, as he described it, as an assault.

According to the criminal complaint, Arndt told police he was with Walker at Gooseberry Park in Moorhead, Minnesota, “when an unknown white male began following them.” Arndt claimed the man stabbed him and Walker then ran into the woods. Arndt was then treated at the hospital for cuts to his fingers.

Walker’s mother then reported her missing to Moorhead Police at around 12:35 a.m. on August 20. The mother said her daughter’s snapCThis location showed an area near a bike path at Elm Street and 6th Avenue South in Moorhead.

Officers then found the girl’s body in the Red River near the trail in a wooded area. Police also found a knife and noted that the girl had wounds to her back, torso and neck.

READ MORE: Teenager arrested after missing Moorhead girl’s body found by river

Suspect’s account

Arndt then spoke to police at a Fargo hospital after being read his Miranda rights, the complaint states. Although he initially told the same story about the unidentified man, he reportedly “told a number of other versions of what happened between him and the victim in the wooded area by the river.”

According to police, Arndt then admitted to having been in a romantic relationship with Walker for several months, but that it had recently ended. Arndt added that the teenager began hitting and kicking him when he refused to tell her who his new girlfriend was.

The indictment states that Arndt then pulled out a knife and inflicted injuries on his fingers before hitting the girl and stabbing her “approximately 13 times”.

Arndt said he then fled the area on his scooter, leaving his phone and backpack behind along the way. He said he then went to his apartment to wash his blood-stained clothes.

The police later obtained a search warrant to recover red-colored items from Arndt’s apartment. They also found the discarded backpack and scooter.

Investigators say surveillance footage and eyewitness accounts place Arndt and the victim in the Gooseberry Park area between 7 and 8 p.m.

A detective later spoke with Arndt at the Cass County Jail. Arndt then gave more details about the incident, admitting that the young girl “was not alive when he left the scene,” according to the complaint. Arndt allegedly said he “slit her throat, hugged her, and stabbed her in the back again” before dragging her to the river and fleeing the area.

What’s next

A further court date had not been set as of Thursday evening.

If convicted, Arndt faces a maximum sentence of 40 years.