St. Cloud police say a Moorhead, Minnesota, man was arrested Wednesday after allegedly poisoning his roommate with thallium earlier this year. 

According to police, a 35-year-old man who's currently being held at the Stearns County Jail intentionally poisoned another man, identified as 33-year-old Cody Ray Ernst, in June. 

Staff at the University of Minnesota Hospital in Minneapolis found Ernst had "an extremely high and lethal level" of thallium in his system after he was admitted. Police say they were notified about his admission on June 20 and add that Ernst was in critical condition at the time. 

Ernst died two days later from what police say are medical complications directly related to ingesting thallium. 

After working with multiple police departments and sheriff's offices across the state, as well as the Minnesota Bureau of Criminal Apprehension and the Federal Bureau of Investigation, police say they found evidence linking the poisoning with the man who was living with Ernst at the time of his death.

Ernst, according to a GoFundMe set up to help with funeral and memorial expenses, has a 14-year-old daughter.