What murder case is this?

I forget how I found it, but I remember reading about a murder on Wikipedia and it was really interesting, but I forget which murder it was. I think it was in the 80's and a new girl moved into town and another girl's girlfriend left her for the new girl. She was mad and got her and her friends to kill either the ex girlfriend or the new girl, I forget who. They lured her out of her house, I think they invited her to go somewhere in the car with them. Anyhow, they put her body in the trunk and later found a place to bury it. The part that stands out the most though was that the article mentions that they were out all night and went to breakfast at McDonald's and they were laughing about what they'd just done.