Cops on Missing Cousins: There May Be a Witness Meanwhile, Lyric Cook-Morrissey's mom agrees to 2nd polygraph By Newser Editors and Wire Services Posted Jul 23, 2012 12:33 PM CDT 3 comments Comments This combo made from undated photos provided by Black Hawk County police shows cousins Lyric Cook-Morrissey, 10, left, and Elizabeth Collins, 8, who have been missing since Friday afternoon, July 13. (Uncredited) (Newser) – Someone may have been present when Iowa cousins Lyric Cook-Morrissey and Elizabeth Collins disappeared on July 13. An FBI spokeswoman said today that investigators want to interview a person who was paddleboating on the lake around the time the girls vanished. She said that person, who has not voluntarily come forward, could help investigators learn what happened to the girls but was not considered a suspect. Meanwhile, Lyric's mom today agreed to submit to a second polygraph test to show she is again cooperating with investigators, sister Tammy Brousseau said. Misty Cook-Morrissey had submitted to one polygraph last week, but had announced she would not take any more after complaining she had been harshly interrogated and accused of involvement in the disappearance. That stance caused some friction among family members, Brousseau said, and in recent days investigators repeatedly called the lack of cooperation a distraction for their search. Authorities believe the girls are still alive.