A young girl runs away from her boyfriend who abused her and end up living with a girl who lives on a farm. The girl she stays with is kind of a whore and always has boys over but the next day they are always gone and there cars are gone. The girls dad is a pig slaughter or something like that and he act really suspicious. The girl eventually after living there a while decides to see what's in the barn and there is dead body's under the ground of the barn or something like that.

I'm not sure what category this movie is in but I'm guesing horror or mystery/crime

Try looking in the SiFi section of your local video rental store.

This is Slaughter (http://www.imdb.com/title/tt1230206/) from 2009.