RIVERHEAD, N.Y. (AP) — Two people were charged with murder on Monday in the killings of a couple whose remains were found scattered around Long Island earlier this year.

Jeffrey Mackey, 39, and Alexis Nieves, 33, pleaded not guilty to killing Malcolm Brown and Donna Conneely, of Yonkers, at their arraignment in state court in Riverhead.

Mackey, Nieves and two other people were previously charged with concealing a human corpse and tampering with evidence in connection with the discovery of body parts in Long Island parks in late February and early March.

Assistant Suffolk County District Attorney Frank Schroeder said in court that Mackey stabbed Brown and Conneely to death and Nieves beat one of them with a meat tenderizer following a dispute over an earlier armed robbery.

“While the case involves the cutting up of bodies of two human beings, the barbarity of those acts were only exceeded by the brutality of the murders themselves,” Schroeder said, according to Newsday.

Mackey and Nieves were arrested along with Steven Brown and Amanda Wallace after police executed a search warrant at the Amityville home that Wallace, Mackey and Brown share.

Suffolk County District Attorney Ray Tierney said Conneely and Malcolm Brown, a cousin of Steven Brown, participated in the planning of the Feb. 20 knifepoint robbery of a gas station that apparently sparked the fatal dispute.

Tierney said at a news conference that Conneely and Malcolm Brown were killed on Feb. 27.

Steven Brown and Wallace have not been charged in the killings, but they still face other charges, including hindering prosecution and concealment of a human corpse. They are scheduled to be arraigned Tuesday.

Christopher Gioe, an attorney for Nieves, said she maintains her innocence. Mackey’s attorney, John Halverson, said via email that he would fight the charges.

Keith O’Halloran, an attorney for Wallace, said he was pleased that his client has not been charged in the killings and that he looks forward to defending her against the charges she does face.

A messages seeking comment was sent to an attorney for Steven Brown.