Tulsa police are investigating following an overnight stabbing that left one person hospitalized in critical condition. 

In the suspect's arrest report, police said Mark Castleman admitted that he stabbed the victim, but claimed it was in self-defense. Castleman told authorities that the victim attacked him when he was asked to leave the apartment he was in. 

Police were called to the Brightwater Apartments on South Phoenix Avenue near West 23rd Street. Officers said they located Castleman trying to flee the scene. 

The victim suffered a stab wound to the neck, and is in critical condition, according to police. Officers have not recovered the weapon, but believe it was a pocketknife. 

According to police reports, authorities found what they believe to be methamphetamine at the scene, and Castleman admitted the drugs belonged to him.