Boston- www.msnbc.com- The same digital technology that a Boston-area predator has used to rob two women and kill another under the guise of seeking a hotel-room massage may help police track him down, former FBI profiler Clint Van Zandt said Friday.

Police believe a young and clean-cut blond man spotted on hotel surveillance videos is using ads for massage services posted on the Internet site Craigslist to victimize the women in hotels. After one robbery and a murder in two luxury Boston hotels, police believe the same man is behind the Thursday night robbery of a woman at a Holiday Inn Express in Warwick, R.I.

The three crimes have occurred in little more than a week. All three women advertised masseuse services on Craigslist.

“We’ve got at least a spree offender,” Van Zandt told TODAY’s Matt Lauer. The surveillance tapes show the man wearing a leather jacket and calmly texting on his cell phone as he left the hotels. Van Zandt said the man is going from one assault to another without the need to take time to calm down, making him even more dangerous.

“It tells us this is a guy who’s not new at this, that he has been involved in other robberies, perhaps other sex crimes, perhaps other murders,” Van Zandt said.

The first attack took place last week in the Westin Copley Place Hotel in Boston. The 29-year-old woman was bound with plastic cord and robbed of a debit card and $800 in cash. The same type of plastic cord was used to tie up the victim in the Rhode Island attack.

“Everything about the crimes leads us to believe they’re connected,” Boston Police Chief Ed Davis told NBC News.

The suspected spree criminal became a murderer on Tuesday in the luxury Marriott Copley Place, located in the same downtown Boston area as the Westin. This time, the victim, 26-year-old Julissa Brisman of New York, apparently attempted to fight the man off after he tried to rob her. She was found in the doorway of her room, dying from several gunshot wounds to the torso.

“I thought, this is so brazen,” Van Zandt said. “This guy is just casually walking out, in this case after pumping three or four rounds into a woman and leaving her dying in a hall in a hotel … He’ll do it again if police don’t catch him.”

Although police say they do not yet have leads to the suspect’s identity, Van Zandt said the same cell phone and Internet technology the man has used should help police.

“Between cell phone calls, e-mails he would have traded with the victim, I would guess law enforcement is only a couple of steps behind him right now,” Van Zandt said.

The suspect, Van Zandt said, probably lives in the Boston area.

The suspect’s calm demeanor in surveillance photos indicates he is experienced and dangerous, according to former FBI profiler Clint Van Zandt.

“This is a guy who lives, who works, who has family somehow in that Boston area,” he said. “Something set this guy off within the last week or so, a need for money for drugs or something like that. If he can get a woman by herself, she becomes a very easy victim.”

The attacks come a week before a flood of visitors arrives in Boston for that city’s annual marathon. Hotels have stepped up vigilance for the event.

“In light of the incident on Tuesday night, we heightened security, as much in an effort to kind of appease any potentially frazzled nerves than anything else,” said Lucy Slosser, a spokeswoman for the Marriott Copley.

Paul Sacco, president of the Massachusetts Lodging Association, said he spoke to several hotel managers Thursday.

“Naturally, it’s a concern. Basically, we are going into a marathon weekend, a very busy period,” he said. “But I have to say that hotels are some of the safest places to be. They have 24-hour security. These two rather terrible and isolated incidents, I feel, are just that.

Police said that they believe the victim at the Westin was involved in prostitution, but that they are uncertain about Brisman.

“What we know is that Miss Brisman was advertising masseuse services on Craigslist,” said police spokeswoman Elaine Driscoll. A massage table was found in her hotel room.

A spokesperson for Craigslist did not immediately respond to a request for comment. The company has said it cooperates with law enforcement and works to prevent inappropriate use of the site.

Brisman’s killing appears to have rattled other masseuses who advertise on Craigslist in Boston.

One poster included a news article about the killing and wrote “Very scary!!” under the headline: “YOU MUST READ THIS…”

Brisman’s friends said they didn’t know she had advertised herself as a masseuse.

Masseuse Julissa Brisman was found dying of gunshot wounds after apparently attempting to fight off her attacker.

Matthew Terhune, 34, a photographer from New York City, said Brisman, who sometimes modeled for him, told him she had been paid $1,000 to fly out to private parties in Chicago and walk around in a bikini or topless. “But I don’t think it went beyond that,” Terhune said. “They were just parties where guys wanted to see hot girls.”

Makeup artist Emily Claire, 30, Terhune’s girlfriend, worked with Brisman during the photo shoot. She said Brisman, a recovering alcoholic, wanted to eventually become an Alcoholics Anonymous counselor.

“The last time she was here, she went to an AA meeting,” Claire said.