How to Be a Reliable Witness in a Brutal Case

How reliable could a four-year-old be when it comes to being a potential witness in a brutal case like this? There's no easy answer to that. All kids are different and they have different capabilities at that age. It's very difficult without knowing the child. I know that there was a Tom that was in my mom's diary and they had questioned him. He was a guy that my mom actually had went to high school with. She dated him a couple times, but it wasn't a love connection.