Tulsa police are investigating a stabbing that happened at an apartment complex near 9th and Sheridan.
According to police, it all took place on Thursday night at the Melrose Apartments.
Police said that when they arrived on the scene, they found a male victim had been stabbed in the arm.
Officers believe the man's ex-girlfriend stabbed him after he showed up at her apartment.
Authorities said they did not see any signs of forced entry into the unit, but say the victim did not invite him inside.
Officers did make a tourniquet to stop the bleeding while the man went to the hospital.
According to police, they have had run-ins with this same person before.
"We've been here several times for domestic-related calls, unfortunate types of outcomes related to those," said Sgt. Paul Madden with the Tulsa Police Department.
Currently, officers are still investigating, but believe this was an act of self-defense.
Police are interviewing the victim as well as the suspect who is being treated at the hospital for their arm injury.