Might have been a British movie; not sure. I saw it on TV in the late 70s or maybe as late as 81.
The main character is a boy and for some reason there’s a bad man looking for him. The man has a gun and–maybe this is just my distorted childhood memory, but when he kills someone with it, their bones get exposed in some weird way. It’s not gory, just weirdly exposed and scrambled bones. The one person I remember the man killing was a young girl who tries to help the boy; she’s around the same age. I think a lot of scenes were dark–night time exterior. Thanks!