Katherine Ann Olson, 24, wanted to earn money to help pay for graduate school in Madrid so she looked online and spotted a woman looking for a babysitter. Katherine and the woman, whose name was Amy, exchanged emails and Katherine agreed to babysit her daughter. She commented to her roommate that Amy seemed strange, but she ignored her instincts and headed off to her babysitting job. Katherine had no idea she was about to meet a man without a soul.Philip Markoff seemed to have it all. He was in his second year of medical school, he was young and nice looking and he was engaged to be married. But then there was another side to Markoff, a darker side, that those closest to him never knew existed. But to his victims that he met through Craigslist, it was the only side of him they ever saw and it cost one of them her life.Dao Xiong was 19 when he used Craigslist to connect with a man wanting to sell his Nissan 350z. The father of four, Youa Ty Lor, was planning to use the money to invest in his new business. But when the two met, Xiong&#39;s true intentions surfaced and Xiong wasn&#39;t interested in <em>buying</em> anything.Alexander Lyons and Lamar Clemons used Craigslist to connect with a young man who wanted to buy a new cell phone. Jonathan Clements, 19, told his aunt he was excited because someone had answered his ad. What he didn&#39;t know was that it was all a setup and that the stranger he was heading down the street to meet was willing to kill for the price of a used cell phone.