Hello, It Was In The Evening And In A Public

Hello,

It was in the evening and in a public place with a huge crowd where I was crossing the road to get the bus. While crossing, a person passed beside me and very close to me. I just thought his hand hit my thighs. When I took few more steps, I realized that it was a pin prick. I saw that pin was stuck to my pant. I just threw it once i saw since i was tensed without noticing if it was needle/something. I also saw blood stain on my pant only in that area. I am not sure what he injected but he was holding something in his hand but it dint look like a syringe which doctors use to give injections. I am not sure if you get any other syringes also. Can you tell me if there are any chances of him injecting something?