Protection while hiking

I was recently at work assisting a client and he had asked me if I had ever checked out a local hiking spot. He must have overheard me talking to someone else that I enjoy hiking. I told him that I hadn't and he asked if I frequently hike alone to which I said sometimes. After he made things very awkward by giving me his number if I wanted a hiking partner, which I wasn't interested in. Afterwards my boss had come up to me I had mentioned that the customer had given me his number and I had thrown it away. She then looked very worried and had said that she knew him when they were teenagers and that he had been arrested for sexual assault. Afterward, I became uncomfortable and I started thinking about hiking alone. I currently hike with a pocket knife in my pocket but otherwise hadn't much thought about what else to bring for protection. Does anyone else have any things they do when they hike alone?