Get her over her fear

having a fear of the dark is a very common fear a lot of children and even adaults have a fear of the dark first you should probably address the cause of it you say shes afraid of murders so perhaps shes been watching too many scary movies or crime shows on television that could make her scared at such a young age try to reduce the amount of those things she watches especially at night time or near her bed time then you can work on ways to make her a bit less scared try introducing a night light in her room quite a lot of people “feel” safer if the room isnt completely dark or if its something in there shes afraid of (like a closet) maybe talk about having it removed or covered up if light doesnt make her feel safe maybe noise might and you could try getting her a radio and putting it on a channel that doesnt play crap like pop, rnb, ect so the room is noisy, not too loud thugh and that could help her you can also talk to her and tel her that theres nothing to be afraid of and maybe buy her a big fluffy toy that she can take with her to be and you can tell her that the toy will make her safe and protect her while shes sleeping hope all that helped :]