DeBARY, Fla. -

A DeBary family wants to know who or what beheaded their autistic son's pet chickens over the weekend. 

The Harts said they built a chicken coop in the spring after a doctor suggested the animals would benefit their autistic son. Two-year-old JJ Hart uses them as therapy.

According to Joe Hart, JJ's father, investigators from the Volusia County Sheriff's Office originally told the family the chickens' wounds appeared to be human-inflicted.

"My wife even begged him to say it was an animal so she wouldn't have to worry. The investigator said in all his years, he had never seen an animal attack like what happened to my chickens," Hart said.

However, investigators told Local 6 they did not find any sign of entry or footprints near the backyard coop and that some of the pictures of the dead chickens show what appear to be bite marks. Investigators said this had led them to believe that the chickens were actually beheaded by a wild animal.

Hart said three of the chickens that were killed were locked inside a smaller cage within the coop. He said he doesn't understand how an animal could have gotten inside the cage.

Donna Cheney, JJ's grandmother, said the toddler has noticed that Arlina, his favorite chicken, has been missing.

"Maybe it's not a dog, not a typical pet, but it's what JJ has related to and he helped raise those chickens from the palm of his hand," she said.

Cheney said JJ's siblings are scared of what else might happen.

"The three-year-old, he stayed with me the entire weekend because he was like, 'They're gonna kill me?'" Cheney said.

Last week week, a code enforcement board said the family was in violation of a city ordinance by keeping the birds in the back yard. The Harts were given 60 days to appeal to the Debary City Council. The family said they will make their case on Nov. 7.

In the meantime, the Harts said they will keep the public updated on their cause via Facebook.

The family has also created a petition on change.org.

Watch Local 6 News for more on this story.