Just before 2 a.m., officers responded to Wesley Avenue after area residents contacted police regarding a domestic violence incident.
Arriving officers allegedly overheard Tim Willwerth apologizing to his girlfriend for stabbing her.
Officers entered a home and found the girlfriend with a single stab wound to her left upper arm. She was transported to a local hospital for treatment.
Willwerth was arrested for domestic violence and assault with a deadly weapon, according to the Police Department.