Cant remember name of a movie I watched when I was young

When I was really young I watched a film that I have a very vague memory of and I cant find out anything about it. The film starts off at the beach with a close up on a gun pointed at someone and when it fires it is actually just a kid with a squirt gun. The film is pretty old but it was in color. The only other details I remember are that it is a murder mystery I'm pretty sure and one of the murders, the guy is killed by getting his head frozen other than that my memory is super hazy, if anyone knows that film I am talking about please comment!