hints at a possible motive for the attack. >> i don't know why they have done this, i really don't. i guess they want the insurance money, i'm not sure. >> reporter: the call lasts about five minutes and ends with chilling silence. >> i want you to lock your door, okay? >> they just -- i just heard them say where did mom go? they're headed upstairs now. >> hello? >> the police are on their way. they're on their way. >> hello? hello? hello ma'am? >> yvonne ervin is back home tonight, her husband, zachary, who suffered the brunt of the attack is still in the hospital. he is listed in fair condition. authorities say the motive behind the attack is still