These bastards were too tight-lipped. Although the first guy did say something, it is not something I didn't know so the info he gave was pretty much useless. The only useful thing I got was the tip they have for what they were currently looking for.
I managed to get rid of them by smacking the back of their heads, knocking them out effectively. They have a 50-50 chance they will wake up later with their memories intact but I made sure that they will also pay for what they did. I didn't bother to call the police due to the reason of breaking their fingers. This will cause me to be questioned by the police in the end. I decided to throw them into the heap of a trash dump in the neighborhood and made sure to cover them with garbage.
They cannot say who I was since they also don't know my real identity. They can only try to guess who I was.