ABC News: Weeks after the FBI monitored the payment of $15,000 to Joran van der Sloot by an alleged extortion victim, the Dutch playboy took a seat at a poker table in a Peruvian casino where he would meet the woman whose battered body would later be found in his blood smeared hotel room. U.S. authorities told ABCNews.com that they launched an extortion investigation of van der Sloot six weeks ago, before Stephany Flores Ramirez, 21, was found beaten and stabbed to death last week. U.S. investigators said they did not issue a warrant for his arrest until this week because they lacked sufficient evidence.