The case against Bronson K. Iseri, who was indicted in September, is one of at least three involving erotic services ads on Craigslist under investigation by the U.S. attorney general's office in Hawai'i, officials said this week. Charges have not been filed in the other cases.

BOSTON SUSPECT

Larry Butrick, criminal chief at the office, said Web sites like Craigslist have brought a new dimension to prostitution and sex trafficking that law enforcement is still trying to tackle.

"I think that we're not even scratching the surface," he said. "It's such a vast resource for predators."

Craigslist, best known for garage sale and houseware ads, has been thrust into the media spotlight in recent days after the murder in Boston of a woman who advertised "massage services" on the site. Philip Markoff, a medical student suspected in the case, is also accused of robbing another woman who had placed an ad on the site.

The crimes are prompting some calls for increased oversight at Craigslist.

In response, Craigslist CEO Jim Buckmaster has said he intends to play a larger role "with respect to Internet safety and security." That's on top of changes made last year to the erotic services section of the site, which included requiring a fee, credit card and phone number for ads. Law enforcement agencies can subpoena that information, under a deal reached with states.

EROTIC SERVICES ADS

Though there are other networking Web sites where prostitution ads can be found, officials say Craigslist appears to be the site of choice for pimps and "freelance prostitutes" because it is easily accessible and gets lots of Web traffic. A scan of the Web site this week showed dozens of ads for erotic services statewide, most of them on O'ahu.

The ads are careful in their wording — asking, for example, for "roses" instead of cash.

It's unclear how many arrests locally have been made because of erotic services ads on Craigslist or other sites, largely because police do not track the statistics separately from other prostitution arrests. But HPD's Dowsett did say that the recent HPD sting is part of an increased effort to crack down on Internet-based prostitution in Hawai'i, which can often be linked to other crimes, "including child sex trafficking, drugs, weapons and exploitation of ... immigrants."

She added that prostitution ads on Craigslist and similar sites have "changed the patterns of prostitution," making it easier for prostitutes to get clients and evade police.

"The Internet is a more discreet way for people to meet prostitutes," she said. "Prostitutes are using laptops and cell phones to arrange encounters for money, then moving on to the next location."

RURAL ACCESS

Sites such as Craigslist, officials say, also are used by prostitutes to offer services in rural parts of the Neighbor Islands, which had previously seen little to no prostitution. Police said the recent Kaua'i case is believed to be the first Internet prostitution sting there, but comes as officials are seeing more prostitutes offering services in rural parts of the Neighbor Islands.

Tracy Ryan of Arresting Prostitutes is Legal Exploitation, which advocates for decriminalizing prostitution in Hawai'i, said the advantage of Craigslist for prostitutes is that they can work without a pimp, though she pointed out that some pimps also post ads.

The big downside is that prostitutes can't easily assess whether a client means harm.

"On the street," she said, "at least you see the person."