BOSTON, Massachusetts (CNN) -- A 22-year-old medical student suspected of killing a woman he may have met through a Craigslist online ad was arraigned Tuesday and will be held without bail. Medical student Philip Markoff, 22, appears in court Tuesday in Boston, Massachusetts. Philip Markoff, a second-year student at Boston University's School of Medicine, listened intently but did not speak during the hearing in Boston Municipal Court. Dressed in a blue-striped shirt and slacks, Markoff was handcuffed and wearing leg irons. His attorney, John Salsberg, told reporters after the hearing that Markoff is "not guilty of the charges. He has his family's support. I have not received any document or report or piece of evidence other than what I heard in the courtroom. All I have at the moment are words -- no proof of anything."
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Not-guilty plea entered in Philip Markoff's behalf in woman's slaying in Boston
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Prosecutors say semiautomatic firearm found in search of student's home
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CEO says Craigslist looking for ways to make site safer in wake of killing
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E-mail from suspect's fiancee says police have "wrong man"
There may be more victims that authorities are unaware of, he said, adding that the prosecutor's goal is to hold @placeholder accountable, not to pursue women who may be advertising on Craigslist.