Polygraph Testing Process News Today

Welcome back to "hardball." american investigators are in colombia this week looking into the prostitution scandal rock the secret service right now. according to a u.s. official, some of the age ens now back in states have been offered polygraphs as part of their investigation. and some have accepted the clans it take one. nbc news correspondent kristin walker is at the wlous with the latest. kristin, a sorted story to report bp what do you got? >> reporter: certainly is. it continues to evolve...