Five women have been arrested in what detectives are calling the first prostitution stings in Island County history.

To the surprise of investigators, three of the women are Oak Harbor residents and they were allegedly prostituting themselves purely for money in tough economic times. Drugs didn’t appear to be a factor, as it often is in such cases.

The two undercover operations were made possible by Craigslist, an Internet site featuring free classified ads. Men and women in “the oldest profession in the world” use the modern technology to advertise themselves, making prostitution easy and available in nearly all corners of the nation.

It’s a widespread problem that state Attorney General Rob McKenna is trying to crack down on. He recently reached an agreement with Craigslist officials requiring people posting ads for erotic services to provide a phone number and pay a fee.

In Oak Harbor, detectives have only investigated a few scattered prostitution cases over the last three decades or so. But after researching Craigslist, the cops are pretty sure that prostitution has become more prevalent on the island.

“We’ve always heard that it was here, but the computer age really brought it around,” said Lt. Tim Sterkel with the Oak Harbor Police Department. He added that the last time he remembers detectives conducting anything similar to a prostitution sting was a massage-parlor case in the late 1970s.

“I think we’re just scratching the surface now,” he said.

Detective Mike Bailey said he started looking at the Craigslist site based on a tip and discovered a number of women, as well as a man or two, offering sex for a price in the Oak Harbor area. He also found another distressingly seedy activity advertised on the site, but police determined it wasn’t criminal.

The original hooker-related tip, the detective said, came from a resident of a neighborhood in the southwest section of the city. Neighbors complained that a house in the area was basically a brothel and one person noticed it was advertised on Craigslist.

The detectives never found incriminating evidence about the house, but Bailey said he discovered a number of prostitution ads for the Oak Harbor area under the “erotic services” category. Some of the ads included explicit photos and most set a “donation” price for “in calls” or “out calls.” The usual cost is $150 for a half-hour.

“No matter how they phrase it, the bottom line is it’s an exchange for a sexual act,” Bailey said.

While prostitution itself is only a misdemeanor crime, Oak Harbor Police Chief Rick Wallace said detectives felt that an investigation may uncover more serious crimes, such as drug dealing or pimping. But that didn’t pan out.

“They thought they might find exploitation of prostitutes and abuse,” Wallace said.

A team of investigators from the Oak Harbor Police, the Island County Sheriff’s Office and the Naval Criminal Investigative Service set up a sting operation on Oct. 24. The NCIS was involved, the detective said, because there was an indication that at least some of the clients or “johns” are members of the Navy. Some of the women even advertised military discounts.

An NCIS special agent called a number of the women in the ads and set up “dates” at a motel in Oak Harbor. In the phone conversations and in the hotel room, the agent and the women discussed explicitly what sexual acts she would perform for certain amounts of money, Bailey said.

NCIS provided surveillance equipment so that a group of detectives could watch from next door and swoop in for the arrest once the undercover agent gave a pre-arranged signal.

The agent set up dates with seven women, but only three showed up at the hotel and were arrested.

Then in November, the team set up a sting to catch two more women. The agent arranged separate rendezvous with them in a car parked in the Safeway parking lot. Both women were arrested.

Bailey said he was surprised that three of the five women arrested in the two stings are Oak Harbor residents, ages 19, 20 and 21. Officers also arrested a 20-year-old woman from Whatcom County and a 26-year-old woman from Snohomish County.

The arrests went smoothly, Bailey said, though one woman had an illegal butterfly knife on her and was verbally abusive to officers. In fact, he said the woman claimed she wasn’t really a prostitute, but planned on robbing her client.

“Armed robbery is a much more serious offense,” Bailey pointed out.

Wallace said an individual was identified as a possible pimp, but police didn’t have evidence to make an arrest. None of the women had any drugs on them or appeared to be drug users, though one woman admitted to smoking marijuana, Bailey said.

A couple of women said they resorted to prostitution because of difficulty in finding a good job. A number of them started after hearing about women making money for sex through Craigslist.

“Some of them have been doing it longer than others,” Bailey said. “Some are just starting out.”

It’s undoubtedly a dangerous profession. According to Bailey, some of the women admitted they had been ripped off by clients in the past.

“The opportunity for money for them outweighed the risk of getting arrested or assaulted,” the detective said.

Bailey said the women are using Craigslist to establish a regular clientele. He said the area is apparently a competitive market, with alleged prostitutes “flagging” each others’ ads on Craigslist.

The women’s clients can rest easy. Bailey said the alleged prostitutes didn’t divulge any names of people who paid for sex in the past.

The police did not release the women’s names since the city prosecutor hasn’t made charging decisions yet.

Bailey said Craigslist has exposed Oak Harbor’s unwholesome underbelly, but there’s a limit to what police can do. He came across an advertisement on Craigslist for a “glory hole” at an Oak Harbor home. The ad offered an anonymous sexual act through a hole in a door.

Detectives did some investigating and determined the ad didn’t appear to be a hoax, but they found no laws were being broken. Still, they worry about a potentially dangerous situation.

“You have no way of knowing what’s on the other side of that door,” Bailey said.