Aunt: Mom of missing Iowa girl agrees to polygraph - WQOW TV: Eau Claire, WI NEWS18 News, Weather, and Sports

EVANSDALE, Iowa (AP) -- The aunt of two missing Iowa cousins says one of their mothers has agreed to take a second polygraph test to show she's cooperating with investigators.

Tammy Brousseau said her sister, Misty Cook-Morrissey, was going through the so-called lie-detector test Monday.

Cook-Morrissey is the mother of 10-year-old Lyric Cook-Morrissey, who vanished with her 8-year-old cousin Elizabeth Collins while riding bikes July 13.

Cook-Morrissey had taken one polygraph test last week, but said she would not take another after complaining she was harshly interrogated and accused of having something to do with the disappearance.

Brousseau says that position caused friction within the family and investigators to complain of a lack of cooperation. She says Morrissey agreed to the second test on the condition that she could have a family member present.