A 73-year-old man was stabbed Monday at a downtown branch of the Madison Public Library, 201 W. Mifflin St.. The victim was stabbed by Erik Petterson, 33, from Madison, according to Madison Police Public Relations Officer Emily Samson.

Samson said both Petterson and the suspect were volunteering at a Green Party event when the victim touched the suspect and made him uncomfortable.

“The victim somehow touched the suspect. Whether [Petterson] bumped up against him or inadvertently touched him, the suspect didn’t like it,” Samson said. “It made him feel uncomfortable and [he] in turn took out his pocketknife and stabbed the victim in the chest.”

The victim was stabbed in the chest over his right shoulder. Police responded to the event at 8:17 p.m., according to a police release.

According to Samson, the victim was admitted to a local hospital overnight. The victim’s age was a primary concern for his well-being, while his injuries were reported as being non-life threatening.

Following the stabbing, Petterson did not flee from the scene or try to get away, Samson added. When officers arrived he was upset, fearful and overtaken by what had happened, according to Samson.

“The suspect was waiting for police to arrive,” Samson said. “These kinds of issues are of concern for us. There was an issue other than criminal activity going on at the time.”

Petterson was arrested and then taken to Mendota Mental Health, according to a release.

Samson said stabbings are not a common occurrence in Madison and this specific case involved more than violence.

“This is more a case of someone with some mental health issues who just lost it. It was an unfortunate time for the victim,” Samson said.

Petterson had a restraining order brought against him in January 2002, as well as a disorderly conduct charge in October 2002, according to court documents.