Update at 6:37 p.m. ET: Investigators are saying two Iowa cousins who disappeared a week ago have been abducted after a search of the lake where their bikes were found came up empty.
Cousins Lyric Cook-Morrissey, 10, and 8-year-old Elizabeth Collins, went missing July 13 while the pair were riding bikes near Meyers Lake in Evansdale.
Investigators began draining the lake Monday, but stopped at the FBI's request so divers could conduct a search with special sonar equipment, The Associated Press reported.
The sonar doesn't work in less than six feet of water.
Black Hawk County Sheriff Chief Deputy Rick Abben told reporters at a news conference Friday that evidence was collected and sent to a lab to be tested. He did not say what the evidence was.
The announcement comes the same day a judge put Lyric’s father, 36-year-old Daniel Morrissey, on pretrial supervision until September when he is scheduled to face drug charges.
Authorities said Morrissey and his wife, Misty Cook-Morrissey, 34, stopped cooperating with police as of Thursday, The AP reported.
The AP reported Abben said neither is considered a suspect and wasn't sure why they had stopped talking with police.
Cook's sister, Tammy Brousseau, told the AP the girl's parents felt like they were being treated as suspects. Both stopped cooperating after their attorney advised them to do so.
"They've been cooperating with the police 100 percent, but because police don't have a silver Cadillac that tore off with the kids, they don't have no leads," she told AP.
Cook told the Des Moines Register Thursday that Daniel walked out of a police interview earlier in the week after police accused him of killing the two girls.
Authorities also have sifted through trash, examined a laptop and computer, and dug into the parents' past criminal histories.
Cook has a meth-related drug charge from 10 years ago and Daniel has multiple drug charges along with burglary and domestic assault.
Morrissey is charged with possession of methamphetamine with intent to deliver conspiracy to manufacture methamphetamine and other crimes.
The Register reported Morrissey's eight-year marriage to Cook has been rocky at times. The domestic assault charges stems from a 2011 incident where Cook told police he smashed her face into the floor and placed his knee over her neck, making it difficult for her to breathe.
Brousseau told the station the pair had a no contact order with each other but has since been modified since both girls went missing.
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