Investigators uncovered 117 dead dogs at a northern California animal rescue sanctuary, with many of the canine remains having evidence of gunshots.

Miranda’s Rescue, a sanctuary outside Fortuna, California, described itself as a “no-kill” facility. Investigators said the organization accepted hundreds of dogs each year from shelters across the San Francisco Bay Area in return for hundreds of thousands of dollars in funding.

The Humboldt county sheriff’s office announced on Friday that investigators had completed their excavation of the property, marking the latest development in a months-long investigation. Acting under a search warrant for grounds and buildings for evidence related to animal cruelty and fraud, crews dug through areas of the property where authorities believed dogs had been buried in mass graves.

“During the excavation, investigators recovered 117 intact canine remains from two dig sites. An additional 21 canine skulls, hundreds of bones and six loose microchips were located in another dig location near where the intact animals were discovered,” authorities said in a press release.

Before excavation began, investigators used ground-penetrating radar to locate irregularities beneath the surface. Along with the intact remains, they also found several loose microchips that investigators are now trying to connect to specific dogs.

According to the sheriff’s office, the 117 dogs were found in varying stages of decomposition. At the scene, 70 of the animal bodies underwent X-rays, with investigators saying many of the corpses appeared to contain bullet fragments.

Most of those dogs had microchips, and analysts are working to identify them using that information. The other 47 dog bodies were taken into evidence but were not examined at the site because investigators ran out of time.

“Sheriff’s investigators also located an area inside a barn believed to be where the dogs were likely killed. In that same area, investigators located more than 600 dog collars,” the press release said.

A statement posted 18 June on the sanctuary’s website by founder Shannon Miranda addressed two incidents that he said brought increased attention to the rescue. According to Miranda, both cases involved dogs with behavioral problems that he said had threatened employees, volunteers and other animals. He also asked people to withhold judgment until the investigation is complete.

“Miranda’s Rescue is a no-kill rescue,” the statement said. “We do not euthanize animals simply to make space. However, as we state on our website, there are rare circumstances in which euthanasia may be necessary … Whenever euthanasia has been necessary, I have notified local authorities in advance, even when told that reporting is not required.”

It added: “Allegations made without a full understanding of the circumstances can harm not only my reputation but also the future of an organization that has served this community for decades.”

The investigation was launched after a neighbor admitted entering the property without permission in April and digging up what they believed were buried dogs, according to ABC7 News. More than two months later, authorities have not filed criminal charges against Miranda or any members of the rescue organization’s staff.

The sheriff’s office’s press release said it would “like to inform the public that, due to the nature and complexity of this investigation, the evidence review process will require a significant amount of time. Upon completion of the investigation, and after a thorough review of all evidence, if there is sufficient evidence to support violations of animal cruelty, fraud or other applicable laws, the case will be submitted to the prosecution team for review and consideration of criminal charges.”