"After she poked him, he put her in a headlock, walked her from the shallow end of the pool to the deep end of the pool, all the while she struggled," said Robert Biancavilla, deputy chief of the homicide bureau in the Suffolk County District Attorney’s Office, describing Cullen Jr.’s video confession as "chilling".
"He said she struggled violently, and he was surprised a woman of her stature could struggle as much as she did."
According to the New York Post, Biancavilla says Cullen Jr. then dragged her body to the backyard shed and covered it with a small dinghy, before having a shower, and leaving with his mother’s cash and car.
He is then said to have caught a train to his sisters house, who is believed to have then called her father. The father then called police who found her lifeless body where her son had left her.
Despite the video confession, Cullen Jr. has pleaded not guilty and is being held on US$8 million bail.
"He’s quiet. He hasn’t said ‘I’m sorry,’ if that’s what you’re asking," Cullen Jr.’s court-appointed lawyer, Steve Fondulis told reporters outside court.
"At this stage, I have to determine psychiatric background."