Craigslist Killer Arrested, Suspect is 22-year-old Boston Med Student

Philip Markoff is only 22 years old and, by all accounts thus far, he was a regular young man who had a promising future ahead of him. He was a medical student at Boston University set to graduate in 2011 and he was engaged to be married. But police in Boston have discovered a much darker side to Markoff and they arrested him when he responded to another ad on Craigslist for erotic services. Authorities were able to track some of the online communications that Markoff had with his victims back to computers and PDAs that Markoff had access to.

Markoff's fiance, Megan McCallister, sent a letter to Good Morning America explaining that she didn't believe her fiance was capable of hurting a fly. Several other friends and associates of Markoff's have been interviewed by other media outlets and the stories all seem consistent. There was nothing at all disturbing or out of line about Philip Markoff. He was young, good looking and seemed to have his life in order. He had graduated pre-med and was working towards his degree in medicine at Boston University.

But Markoff had apparently been preying on women through the erotic services section of Craigslist and was armed when he arrived to meet them at high-end hotels in Boston and surrounding areas. Markoff is accused of killing one of the women with whom he met and with robbing at least two others in a recent spree of attacks. Markoff was caught on the surveillance cameras of the hotels where he met his victims. People who know Markoff are in disbelief, but authorities seem certain that they have their man.