Board Thread:Episode Discussion/@comment-3125844-20150411001027/@comment-25875828-20150429230437

Kelly left Nick with Mari because they where trying to kill Kelly. That's why Nick's father and his mother's friend where killed in the car. She just let everybody think it was her.

Nick being accused of attempted murder would count as in mortal danger. If nothing else a cop and Grimm in jail would not be a good thing.