Two defendants accused of hiding body parts of two people on Long Island pleaded not guilty to second-degree murder charges.

Jeffrey Mackey and Alexis Nieves were arraigned on the upgraded charges on Monday in connection to the February murders.

Nieves faces 25 years to life in prison. Mackey faces two sentences of 25 years to life, and could face more time on a robbery charge.

Mackey is accused of stabbing 53-year-old Malcolm Craig Brown multiple times. According to prosecutors, when 59-year-old Donna Conneely attempted to intervene, he then allegedly stabbed her multiple times in the neck and tried to strangle her before passing her off to Nieves.

Officials say Nieves then kicked the victim, smashed her with a meat tenderizer and stabbed her in the back multiple times.

According to the Suffolk County District Attorney's Office, the investigation revealed that Mackey, Nieves and Steven Brown had allegedly planned to kill the victims beforehand.

The defendants are accused of dismembering the victims' bodies in the bathroom of the home. Suffolk County police recovered several large knives and two meat cleavers at the Amityville residence where the four defendants had allegedly been staying. Blood was found in multiple locations throughout the residence.

Mackey, Nieves, Steven Brown and Amanda Wallace were all accused of scattering the remains of Conneely and Brown in three locations on Long Island.

Prosecutors say Brown and Conneelly were in a relationship. They say the four defendants and two victims lived together in the same Amityville house where the stabbing took place.

All had previously been out without bail on GPS monitors since their previous arraignments.

Judge has set bail for Nieves at $1 million cash, $10 million bond. She is due back in court on June 3. Mackey was remanded without bail and is due back in court on June 3.

Steven Brown and Wallace are due back in court on Tuesday.