identification

I was wondering about the way using dental records to id a body is seen on tv all the time. Just how realistic is it? I don't imagine that there is any central database for dental records. So is it actualy only used to id about when you suspect you know who it is? That is to say, it's for...

I am examining the following statement: "A tool leaves damage on another object that is unique and distinct to that particular tool." This is in the context of one piece of metal being used to work a second piece of metal. It is claimed that by examining the damage, or tool marks on the second...