Investigators have contacted all the doctors and pharmacies tied to Houston , sources say . Comment: Toxicology results could be completed by March 23 or so , sources say . Houston , 48 , died in her Beverly Hills hotel room ; she had battled substance abuse .
Investigators have contacted all the doctors and pharmacies tied to Houston , sources say . Nothing criminal has been found so far in her death , sources say . Toxicology results could be completed by March 23 or so , sources say . Houston , 48 , died in her Beverly Hills hotel room ; she had battled substance abuse .