The Murder of Brook Baker

It was the spring of 1997 and Brook Baker was a journalism student at Vincennes University in Indiana, working on an expose of one of the fraternities on campus. One night, her brother went to visit her apartment where he found her dead in her bedroom.  In the bathroom, the tub had been left running, and the kitchen sink had been filled with water. As police investigated, their suspect list continued to grow faster than they could eliminate people - there were the brothers of the fraternity, the creepy landlord who would come into her apartment often unannounced, her on again, off again boyfriend. But every lead they went down turned up more questions than answers... 

Sources:

Articles
Oxygen | Bathtub Clues Left At Crime Scenes Leads To Killer Of 2 University Students (Joe Dziemianowicz)

Documentaries
6 Degrees of Murder | Season 1 Episode 6 “Crime Writer”