Murder charges filed in death of Plymouth resident, new details revealed

The Marshall County Prosecutor's Office has filed formal murder charges in the death of Richard Paul Costello of Plymouth.

Maeson Lee Coffin and Gauvin Michael Joseph Monaghan are each charged with one count of murder and one count of auto theft.

On November 5, family members contacted Marshall County Police because they found the body of Richard Costello on his property.

The family members said they hadn't heard from him in about two weeks and became concerned. They went to the property and looked around and located a body near one of the outbuildings.

The body was covered with a blue plastic drum and a large piece of sheet metal, according to the probable cause affidavit.

During the investigation, police discovered Costello's vehicle, a Buick Lacrosse, was missing.

Police pinged Costello's cell phone and the last location was November 3 near Watertown New York.

On November 6, a friend and their mother showed up at the Marshall County Police Department. The friend told police Gauvin Monaghan had the stolen vehicle at his mother's home in Watertown, New York, according to the probable cause affidavit.

An acquaintance told police Monaghan and Coffin had been leasing a residence from Costello. He went to their home on October 27 to collect rent because they had not been paying, reports said.

Monaghan had gotten angry and said he should kill Costello and steal his car, according to the probable cause affidavit.

When the friend saw news reports of the investigation, including the vehicle being stolen, Monaghan's mother was notified and learned Monaghan and Coffin were there and driving a Buick Lacrosse, according to he probable cause affidavit.

Police searched Costello's property and the residence of Monaghan and Coffin. Police said they located items that were blood covered, according to the probable cause affidavit.

Monaghan was apprehended while operating Costello's vehicle in Watertown. A woman he was with told Watertown Police Monaghan said Coffin killed the "guy" and Monaghan helped get rid of the body, according to the probable cause affidavit.

Formal charges were filed on Thursday, November 10.