Soooo..

Ok so recently my fiancés little brother started dating this girl, they're both 15, still in school. About 3 weeks ago they sent my brother in law a msg saying they were going to kill his gf, he told her and she said that's been going on for about a year. She told him they texted her ex, and he left her because of that. They also texted her mother and they've been sending her msgs telling her to be careful when she gets out of school or when she's alone at home, stuff like that because they're going to kill her. She's gone to the police thousands of times, with copies of the msgs and things like that and they've done nothing. This weekend we found out she's leaving to California with her dad because of all this, I was thinking that all of this is just weird, we tried tracking the number ourselves and it just took us to the center of a town near by, we checked online and the number isn't under any name, we called from different public phones and the calls won't go through, we tried taking my brother in law and her to the police station last week and she didn't let us because 'she had already gone'. I know they're kids but it's kind of weird that she's trying to handle everything alone and out of no where she's leaving to California? Is it just me or does something seem off?