Maricopa County Sheriff Joe Arpaio and company say they've found more people surfing Craigslist trying to find dogs that are DTF.

The plan, according to Arpaio, was that the three people arrested by the MCSO last night were using Craigslist to find a dog to "fornicate" with the woman, while her husband and friend watched.

The sheriff's office says all three of their suspects -- Shane Walker, 38, Sarah Dae Walker, 33, and Robert Aucker, 29 -- showed up to the predetermined location, where they met an undercover detective and his male Golden Shepherd mix.

The detective was also offered the "opportunity to join in on the act," although it's not clear exactly what his role would have been.

MCSO Sgt. Brandon Jones tells New Times he "can't disclose" exactly how this operation was set up, but we know it ended up with three people meeting with a detective, his dog, and with expectations of at least one person having sex with it.

UPDATE: According to court documents obtained by New Times, the undercover detective responded to a Craigslist ad posted by the Walkers. The three admitted the plan was for Sarah Walker to have sex with the dog, and her husband, Aucker, and the undercover deputy would join in at some point, according to the documents.

Arpaio's apparently sharp with puns today, as he's quoted in a press release saying, "People who do this for enjoyment are a different breed, that's for certain."

Arpaio also reiterated the fact that he wrote a letter to Craigslist CEO Jim Buckmaster (almost a year ago) asking that he try to prevent the barnyard-banging-type stuff on his website, but Arpaio never got a response.

The sheriff's office says the Walkers and Aucker each admitted to their intentions with the dog, and as part of the Walkers' open marriage, Aucker told detectives he and Sarah Walker "have had a sexual relationship for the last month and that she shared with him dreams of having sex with a dog."

This is now the second alleged dog-sex plan busted up by the MCSO using Craigslist, since two men -- one of them an elementary school teacher -- were arrested in a plot similar to the above-mentioned trio.

The Walkers and Aucker were arrested for "conspiring to commit an act of bestiality," according to the sheriff's office.