By Dan Whitcomb

LOS ANGELES (Reuters) - Police investigating 911 calls from a home linked to Southern California's "furry" dress-up community found two young girls standing on the front porch, three slain bodies inside and a blood-spattered dog, court papers on Tuesday showed.

The documents, published by the Orange County Register, shed new light on the shotgun killings in late September of 39-year-old Jennifer Goodwill-Yost, a woman local media described as popular among the Orange County furry subculture, her husband Christopher Yost, 34, and friend Arthur "Billy" Boucher, 28.

Reuters was not immediately able to obtain a copy of the court documents.

Two men who local media say also have ties to the furry fandom, 21-year-old Joshua Acosta and Frank Felix, 25, were arrested and charged with three counts of first-degree murder.

The furry subculture consists of people drawn to anthropomorphic creatures, interacting as their animal identities online and attending conventions dressed in so-called "fursuits."

According to search warrant affidavits filed on the day of the murder and published on Tuesday, police were called to the beige, one-story home in Fullerton by a child who said that her parents were dead.

Officers arrived to find two girls, aged six and nine, standing on the front porch, the affidavits show. Inside, one of the male victims was dead on the couch, a gunshot wound to his head.

In the bedroom, the officers discovered the body of Goodwill-Yost in a bed, also dead from a shotgun blast, the report said.

The remains of the second male victim were found just outside a doorway to the backyard, with wounds that the officers initially mistook for blunt force trauma, the documents show.

Evidence collected by forensic scientists at the home included items of clothing, shotgun pellets, an orange backpack and swabs of blood from various places, including the door of a Dodge van in the garage and a dog's back.

In the hours after the murders were discovered police initially said that Goodwill-Yost's 17-year-old daughter, Katlynn Goodwill-Yost, had gone missing.

Following the arrests of Acosta, a U.S. Army private based in Texas, and Felix, of Los Angeles, police said Katlynn Goodwill-Yost had been found safe and that an unnamed 17-year-old girl had been taken into custody in connection with the crime.

Authorities declined to say if Katlynn Goodwill-Yost was the third suspect arrested, saying state law barred disclosure of such information about juveniles.

The teen, whose social media pages are replete with pictures of her dressed in animal costumes, has not been charged in the case.

(Reporting by Dan Whitcomb; Editing by Lisa Shumaker)