An argument possibly over $5 ended with one man cutting another with a knife in a wooded area on Butler’s south side Tuesday afternoon, city police said.

Scott H. Fosnaught, 54, who has no known address, is charged with felony assault. He is in the Butler County Prison on $100,000 bail.

Police suspect Fosnaught attacked Mark Graham shortly after 2:30 p.m. in the Clay Hills area between South Monroe and Kittanning streets. Fosnaught claimed he acted in self-defense.

Graham, 51, of Butler was treated at a Pittsburgh hospital for a one-inch deep knife wound to his stomach. His condition was not known this morning.

Police were called after a man came upon the bleeding victim near Clay Hills.

Graham’s injury was described as a 10-inch cut that stretched from the center of his abdomen to his left side across the oblique muscle, according to court documents.

He was taken to Butler Memorial Hospital, where he identified Fosnaught as his attacker, police said.

Graham told investigators that he had confronted Fosnaught over a $5 debt. But Fosnaught denied owing the victim any money, prompting an argument.

Moments later, documents said, Fosnaught pulled a knife from his pocket and threatened to stab Graham.

In turn, Graham recounted, he struck Fosnaught in the face, twice. That’s when Fosnaught allegedly cut Graham and ran off, police said.

Police about 4:20 p.m. found Fosnaught at the Grapevine Center parking lot on North Elm Street. He did not have the knife and claimed he threw it in the woods. Police have not found the knife.

During an interview at the police station, Fosnaught acknowledged the argument with Graham.

Investigators asked Fosnaught if he cut Graham. “He stated that he defended himself,” Capt. David Dalcamo said in an affidavit.

Fosnaught, while never admitting he attacked Graham with the knife, repeated his self-defense claim at least two more times during the interview.

At his arraignment that night, Fosnaught told District Judge Sue Haggerty that he has been unemployed for about 10 years and has been living with a friend in Butler.