Bobbi Kristina Brown Investigation Heats Up: Police Questioning 'Half Dozen' Witnesses — What Do They Know?

Detectives trying to solve the mystery of what happened to Bobbi Kristina Brown are talking to "a half dozen" witnesses about events that transpired in the hours before she was found unconscious in her bathtub, RadarOnline.com has exclusively learned.

Investigators were back inside the suburban Atlanta town home Wednesday looking for clues, according to Roswell Police Chief Rusty Grant. His department opened a criminal investigation on the morning of January 31, after Brown was found unresponsive in her tub, Chief Grant told Radar.

The 21-year-old's friend, Max Lomas, who says he discovered Whitney Houston's daughter in the tub, "will fully cooperate" when he answers police questions later this week, his lawyer told Radar.

Attorney J. Tom Morgan, the former district attorney in neighboring Dekalb County, met with the Fulton County district attorney and Roswell police Tuesday, Lomas' co-counsel John Petrey confirmed. That meeting cleared the way for lawyers to approve another police interview for their client, he said.

Lomas hired Morgan and Petrey after his first interviews with police convinced him he needed criminal lawyers to protect him because of the tone of the questioning, a source close to Lomas told Radar.

Brown, 21, remains on life support in an Atlanta hospital 12 days after Nick Gordon, the man she claimed was her husband, called 911 for help.