Updated

Law enforcement officials in Iowa reclassified the disappearance of two missing cousins as an abduction Friday after an FBI dive team failed to find their bodies in an Iowa lake.

Ten-year-old Lyric Cook-Morrissey and 8-year-old Elizabeth Collins disappeared a week ago while riding bikes near Meyers Lake in Evansdale. Their bikes were later found on a path near the lake.

A special 10-member FBI dive team used sonar equipment on a boat for hours Friday to search the 26-acre lake. Divers waded through the water looking for evidence but did not appear to go beneath the surface. By mid-afternoon, an FBI truck and many other police officers had left and little search activity was going on.

Black Hawk County Chief Deputy Rick Abben told reporters later Friday that the divers were confident the girls' bodies were not in the lake. He also said investigators do not believe the girls got lost because they would have been found by now.

Abben said some evidence in the case has been sent to a state crime lab for analysis, but he would not elaborate on that.

The reclassification came as Iowa authorities took steps to keep a closer watch on Lyric's father, a man with a lengthy criminal history who stopped cooperating with police in the week-old investigation.

Court records showed Friday that a judge has ordered Daniel Morrissey, 36, placed in a pretrial supervision program of the Iowa Department of Corrections while he faces September trials in two separate drug cases. The change means Morrissey, who has been free on bond, will be supervised by parole officers who will make sure he shows up in court and does not violate the terms of his release.

Black Hawk County prosecutor Brad Walz petitioned to place Morrissey under supervision Thursday, the day authorities said he and his wife had stopped cooperating with investigators. Walz cited Morrissey's arrests on methamphetamine-related charges and noted Iowa law allows a person on bond who is considered "a habitual felon" to remain under supervision as a condition of release.

Authorities have said Morrissey and his wife aren't considered suspects and they are not sure why the couple stopped cooperating.

Tammy Brousseau, an aunt of both girls, has said an attorney advised the couple to stop talking to reporters, discontinue television interviews and not agree to take any more polygraph tests.

The order issued by Senior Judge Jon Fister on Thursday said the sheriff's office should deliver the supervision notice personally to Morrissey, who was directed to report to corrections officials immediately after receiving it. Messages left for Morrissey's defense lawyer were not returned.

Morrissey has been charged with possession of methamphetamine with intent to deliver, conspiracy to manufacture methamphetamine and other crimes. He posted bond and was released in May.

Walz said Morrissey should have been placed under supervision then, but he declined comment on what prompted Thursday's order. He said Morrissey faces five charges that carry 45-year prison terms each.

Morrissey's wife, Misty Cook-Morrissey, 34, also has a criminal history, having pleaded guilty in 2003 in federal court to conspiracy to manufacture and distribute methamphetamine, court documents show. She also has theft and alcohol violations in state court and is on supervised release after her probation was revoked in September because of drug and excessive alcohol use and failure to comply with drug tests.

Cook-Morrissey, told KWWL-TV on Friday that she believed authorities were unfairly scrutinizing her and her husband because of their criminal histories. She said she believed police were getting frustrated after searching extensively for a week and coming up empty.

"It's frustrating for us as well," she said.

The working-class community of 4,700 near Waterloo has rallied to show support for the girls even as speculation about what happened to them swirls. Many residents have been wearing t-shirts bearing the girls' pictures and posted hand-written notes to them at the lake. One note urged the girls to "stay strong" and said they had the world's love.

Residents planned to release balloons at a local park Friday evening, and a benefit run for the girls' families is scheduled for Saturday morning in Waterloo.