(Tulsa-AP) -- Tulsa Police say Friday they believe a 17-year-old acted alone in killing a woman and her two teenage sons earlier this week in north Tulsa.
Lorenzo Brown is being held on first-degree murder complaints in the deaths of Karen Chappel and 17-year-old Whitney and 14-year-old Kalin Chappel.
Sergeant Wayne Allen says drug activity by Whitney Chappel is believed to be the motive and that his mother and brother were killed because they were witnesses.
Allen says another man questioned about the homicides was not involved, but remains in custody.
Donald Dennis was questioned after being arrested on other charges in Tulsa and Little Rock, Arkansas.