BOSTON -- Friends and neighbors of Philip Markoff, the Boston University medical student facing arraignment Tuesday for the slaying of a Craigslist masseuse in an upscale Boston hotel last week, said they are shocked at the clean-cut college grad's arrest.

His fiancee said police have the wrong man.

"All I have to say to you is: Philip is a beautiful person, inside and out and could not hurt a fly." - Megan McAllister, Fiancee

"Unfortunately, you were given wrong information, as was the public. All I have to say to you is: Philip is a beautiful person, inside and out and could not hurt a fly. A police officer in Boston, or many, is trying to make big bucks by selling this false story to the TV stations. What else is new?" Megan McAllister, 25, of Little Silver, N.J., wrote in an e-mail to ABC News' "Good Morning America."

In it McAllister goes on to say, "Philip is an intelligent man who is just trying to live his life, so if you could just leave us alone we would greatly appreciate it. We expect to marry in August and share a wonderful, meaningful life together."

Markoff, 23, a 2007 University of Albany graduate, was engaged to be married on the New Jersey shore this August. His fiancee said on the pair's wedding Web site that they attended college together but met while volunteering at an Albany-area hospital emergency room. Both are now in medical school. They became engaged last May.

Now, Markoff has been suspended from the Boston University School of Medicine and is being held in connection with the shooting death of JuLissa Brisman, 26, an aspiring actress and model who was killed in Boston's Marriott Copley Plaza hotel last week during an appointment for massage services.

Surveillance photos in that case and photos taken after a robbery and kidnapping of a prostitute at the Westin Hotel the week before led police to Markoff, who was arrested while driving on Interstate 95 in Walpole Monday afternoon.

Markoff is the son of a Lafayette, N.Y., dentist and a school administrator. He graduated from Vernon-Verona-Sherrill Regional High School in 2004, according to ABC News.

The high school district lies between Utica and Syracuse, and the Oneida County area is "known for its attractive surroundings, convenience to employment, health care, and quality of life," according to the school Web site.

At Markoff's high-rise luxury apartment on Highpoint Circle in Quincy, police executed a search while neighbors expressed stunned disbelief.

"I can't believe he lived here. That kind of scares me. I'm out here all the time with my dog by myself, so it's kind of nerve-wracking to just know that he lived here a few hundred feet away from me. Not even ..." said one female neighbor.

Other tenants had socialized with Markoff a few months ago.

"He was a nice guy. He seemed like it, that's why we invited him up to hang out at our house with a bunch of people. We had drinks and I would have had him over again. He seemed like he was totally normal," neighbor Mike Dye said.

"It's extremely scary because we're friends with everybody around here and, you know, people take out each other's dogs. What if we befriended him to take out our dog and he was in our place, you know? It's just scary to know," neighbor Kym Direnzo said.

"It's definitely creepy. It's definitely a creepy factor to it," said Markoff's next-door neighbor John Uva.