NAUGATUCK, Conn. (WTNH) – Naugatuck police have arrested multiple people, including a New Canaan officer, in connection to an investigation at a dog training facility.

In April, Naugatuck police began an investigation into Black Rock Canines on Hunters Mountain Road after being notified by the Department of Agriculture, Stratford police, and state police about an investigation into David Rivera Jr., as a New Canaan police officer.

David Rivera Jr.

Police investigate at Naugatuck business after complaints of possible animal cruelty

Naugatuck police said it was alleged that numerous canines were abused and injured during their time at the facility. Police said at least 10 dogs were shot and killed by employees and buried on the property by Rivera Jr. and operators of the business.

WATCH: Naugatuck police hold a press conference following the arrests of multiple people in connection to an investigation at a dog training facility

New Canaan police officer arrested on explosives, weapons charges

Police said the remains of four dogs have been discovered on the property.

Naugatuck police also arrested Daniel Luna of Waterbury, who is the general manager of the facility. Police said Luna allegedly abused numerous puppies and dogs and is accused of shooting dogs that were deemed no longer viable for the business.

Police said Luna is accused of leaving puppies exposed to harsh weather elements.

Witnesses reported that military-grade explosives were being improperly stored at Black Rock Canines and the explosives were transported to the Naugatuck Event Center on numerous occasions. These explosives were said to be improperly stored in Tupperware containers and handled by employees who had no training.

On April 29, Naugatuck police were dispatched to Black Rock Canines for the report of employees being threatened. Naugatuck police said David Rivera Sr. allegedly threatened a current and former employee with a knife. He was arrested and released on a $25,000 bond.

David Luna

On May 2, Rivera Jr. and Luna turned themselves in to police. Rivera Jr. was charged with conspiracy to commit cruelty to animals, reckless endangerment in the first degree, and conspiracy to commit euthanization of a canine. He was given a $150,000 bond and will be in court on May 18.

Luna was charged with cruelty to animals, conspiracy to commit cruelty to animals, reckless endangerment in the first degree, unlawful euthanization of a canine, conspiracy to commit euthanization of a canine, and identity theft. He was held on a $225,000 bond and was arraigned on Tuesday.

David Rivera Sr.

On Tuesday, Naugatuck police executed a search and seizure warrant at Black Rock Canines and removed the 31 remaining dogs. They have been placed in shelters.

Stay tuned to News 8 for updates on this story.