Police investigating the slayings of seven women whose bodies were found over the weekend in Indiana say the suspect has told them that he may have killed people going back 20 years. Hammond Police Chief John Doughty said during a news conference Monday that the suspect, identified as Darren Vann, is being cooperative with investigators. Vann was convicted of sexual assault in Texas in 2009 and now lives in Gary. Doughty says the victims found over the weekend were killed recently.