DIGHTON – It likely will never be known why five loose dogs attacked and killed a Rehoboth teenager on a Dighton property last month, according to a statement released Friday by the office of the Bristol County District Attorney.

Ryan Hazel was 14 when authorities say five dogs being kept at 2477 Maple Swamp Road attacked and mauled him to death.

An investigation indicated no evidence of foul play and no evidence that any other animals — including other dogs being housed at the property or wild animals in surrounding woods — were responsible for his death, the release says.

All five dogs were euthanized two weeks after the incident — which took place on a large, sprawling, rural site that includes horse stables, a trailer unit, a fire-damaged house and pieces of construction equipment.

The DA’s statement reiterates a press conference held the morning after the attack at Dighton police headquarters — where District Attorney Thomas Quinn stated that Hazel had been dropped off by his grandmother around 6:30 p.m. to check up on and care for the dogs and other animals living there, as per a year-long agreement with the property owner.

When the former Bristol-Plymouth Regional Technical School student failed to return after more than half an hour, police say his grandmother called the boy’s mother, who was out of state.

Police say Hazel’s mother in turn called a neighbor living nearby. It was that male neighbor, they said, who found the boy’s body at the rear of the property.

Ryan was declared dead despite the efforts of the neighbor and first responders to save his life by providing CPR and other life-saving measures, the DA’s release says.

The property owner, identified as Scott Dunmore, was in Boston at the time, authorities said.

Dunmore, 49, according to authorities was cooperative during the investigation and will not be criminally charged with an offense.

Other dogs being kept at the site were not involved and were not loose at the time of the attack, authorities said.

The investigation revealed that Dunmore owned some of the dogs and boarded others for other owners.

The five dogs that investigators said killed Ryan Hazel were four Belgian Malinois, three of which were eight months old and one of which was four years old.

The fifth canine was a 2-year-old Dutch Shepherd, authorities said.

The investigation concluded that Ryan “was experienced in caring for dogs” and “in particular … these five dogs.”

“Ryan was devoted to caring for dogs in a kind and humane manner (and) no evidence points to Ryan’s actions or conduct contributing at all to cause his death,” the release states.

Dunmore, authorities said, “did not follow the appropriate licensing requirements for these dogs.”

But the five dogs had been vaccinated, the press release states.

Investigators included local and state police and laboratory investigators from the Massachusetts State Police.