Time travelling uncle from the future

A cop's brother and the entire family is killed in an apparent murder-suicide, but freakishly the investigator gets a call two weeks later from his deceased niece! The brother was a bipolar gun-owning pill-popping lunatic therefore instantly blamed for the deaths, but calls from the other side suggest otherwise. Lots to chew on the script, but once you let go of the thick senselessness, it's an ok a thriller.