(CINCINNATI) -- The Sheriff's Department has said that they will not give up the search for Marcus Fiesel until the case is solved.
But ten days after his foster mother Liz Carroll said he went missing from a Hamilton County park, the hope that Marcus is alive continues to dwindle.
"I have great concern as to whether or not that young boy is still alive," said Hamilton County Sheriff Simon Leis. "I hope he is but like anybody with any common sense, we haven't found him."
Not only has an extremely thorough search turned up nothing, but Carroll remains the only person who can place the three year old at the park on Tuesday.
Leis reiterated the message that Carroll gave at a press conference earlier this week, "if anybody has see that young boy at any time with the parents please call the sheriff's department."
Fiesel was placed with the Carrolls through Lifeway Services, a private foster network hired by Butler County Children's Services to place children in homes. A case worker from the county is still scheduled to visit Marcus once a week.
Jann Heffner of the Butler County Children's Services explained to FOX19 News the reason for the weekly visit. "marcus had a pretty hefty treatment plan and we wanted to make sure he was adjusting to the home."
At the press conference this week, Carroll told reporters that Marcus' case worker was the last non-family member to see him before he disappeared. But now the case worker said that she was told Marcus was sick and she didn't visit.
Sheriff Leis told FOX19 News that the case worker missing a visit is not raising red flags. "if it were a case where every other time Marcus' foster parte said no he's ill, that would have raised a red flag," explained the sheriff.
There were 25 other times in 14 weeks that a case worker saw Marcus and all was well. So there was no reason for concern on August 10th. The concern came August 15th when Marcus went missing.
FOX19 News also learned today that Carroll's daycare license has been revoked by the county because, according to the county, there were other individuals living in the house and the county was not made aware of those residents.
A 10-thousand dollar reward continues to be offered for any information leading authorities to Marcus. If you have information call CrimeStoppers at 352-3040 or call the Hamilton County Sheriff's Department.
Report: Corey McConnell