The former lab mate of Philip Markoff, the 23-year-old medical student who allegedly murdered a masseuse who advertised on Craigslist, said her old partner had a darker side. Tiffany B. Montgomery says Markoff had profound mood swings, and, at one point, she considered telling school counselors that he might be suicidal. "Everbody's right when they say he was nice," Montgomery told the Boston Globe. "He was nice, but he was definitely strange, and he was strange in a dark way." Investigators have also suggested that Markoff allegedly robbed other women he found through Craigslist because he had a gambling problem. Apparently, he received a ticket in April 2008 while on his way to the Foxwoods Resort Casino in Connecticut, and his high school friends said he gambled occasionally.