DANVERS, Massachusetts — The Internet has changed the way people do lots of things, from shopping to filing taxes.

But it’s also changing the face of crime, police and prosecutors say.

The latest example of that is the arrest Friday of three women charged with using the Internet to sell sex.

The three were arrested as a result of a sting set up by Danvers police detectives and were arraigned yesterday on charges of sexual conduct for a fee, stemming from an ongoing investigation into prostitution at motels and hotels along Route 1.

Danvers and Peabody police have been working with the district attorney’s office on an investigation into what may be a growing problem on the North Shore, the use of Internet classified advertising sites to arrange “dates” between prostitutes and their customers at local hotels, according to a summary of the case.

District Attorney Jonathan Blodgett said it’s just one of the increasing types of crime in which computers are finding a new role.

“We’re developing more cases through computer investigations,” Blodgett said yesterday. “It’s a trend that we’ve seen.”

Local police departments are becoming more savvy in developing information and following up leads online, said the Essex County’s top prosecutor. He called Friday’s arrest the result of excellent police work.

On Friday, Detective Stephen Baldassare arranged to rent three rooms at the Motel 6 on Route 1 north.

Then he arranged a series of “dates” with women who were advertising their services on the Web site Craigslist, which includes a category called “erotic services.”

The first woman, later identified as Vanessa Vient, 26, of Lynn, showed up shortly after 5 p.m. and made a deal to perform sex for $200, police said. She was arrested by police who were waiting in an adjacent room.

Shortly after that, around 7:15 p.m., Baldassare made another “date” with a woman who turned out to be Danielle Straccia, 25, of Revere. Her alleged price was a little lower, $180. She, too, was arrested by police officers.

Finally, around 8:20 p.m., the third woman, identified as Fatima Borges, 19, of Tewksbury, showed up and allegedly negotiated an even lower price of $150 for her services. She was then arrested.

The three women were all charged with sexual conduct for a fee. They were released on personal recognizance and appeared in court for arraignment yesterday morning before Salem District Court Judge Michael Lauranzano, where they pleaded not guilty. All three women are due back in court April 28 for a pretrial hearing.

Danvers police said disturbances at budget motels along Routes 1 and 128 prompted the prostitution sting, as did checks for warrants on the guests.

The registers at motels and hotels are open for police inspection, police Chief Neil Ouellette said.

What patrol officers were finding in the daily checks is the guests had warrants and an extensive criminal history, including prostitution.

“We decided that we should do some enforcement,” Ouellette said. “We had intelligence and complaints (regarding soliciting sex online). It’s not uncommon for this to happen.”

In Peabody, Capt. Dennis Bonauito said, police are also looking for illicit activity stemming from the Internet.

“The ability to advertise and seek out these kinds of things online is greater,” Bonauito said. “It’s easier for people to find out about.”

Peabody and Danvers are attractive locations because they’re just 15 minutes north of Boston, with easy access to Interstate 95 and Route 128.

“I believe the people are using motels to do this because it’s convenient, centrally located, easy on, easy off the highway, and you can rent a room for a 24-hour block,” Bonauito said.

Blodgett also said that the location of the motels along Route 1 is an attractive location for criminal activity of all sorts because of its easy access.

The use of Craigslist to sell sex is well-known by law enforcement nationwide.

Last week, an Illinois sheriff filed a federal lawsuit against Craigslist for creating “the largest source of prostitution in America.”

The Web site denied the sheriff’s contention and said it cooperates with law enforcement agencies.

Last November, Craigslist reached an agreement with 40 states (not including Massachusetts) that requires people who post an ad for erotic services to provide a working phone number and pay a fee with a valid credit card.