The cause of death Bobbi Kristina Brown's sealed

The medical examiner has determined the caused of death for Bobbi Kristina Brown, but a judge has ordered it sealed pending possible homicide prosecution

From TMZ 

Bobbi Kristina's cause of death is now known, but no one's talking, because police are still on the hunt for evidence that could lead to a homicide prosecution. The Fulton County Medical Examiner just said it knows exactly what killed Whitney Houston's daughter, but they can't reveal it to the public because a judge ordered the findings sealed.