Roy Kronk discovered Caylee's remains in December 2008 in a wooded area near the Anthony family's Orlando home.
Casey Anthony's attorneys began questioning Kronk on Tuesday about an August 2008 visit to the same area when he thought he saw something suspicious in the woods. Kronk had called authorities three times over the next three days but they found nothing at the time.
Kronk returned to the area in December 2008 and discovered the bag containing Caylee's remains.
Earlier in the day, a former search leader used his constitutional right against self-incrimination to avoid answering a question during testimony.
Defense attorney Cheney Mason was asking former Texas Equusearch team leader Joseph Jordan why his testimony Tuesday about knowing the location where 2-year-old Caylee Anthony's remains were found differed from previous statements he gave to law enforcement.
Mason eventually asked Jordan if he'd ever been threatened with felony prosecution, and Jordan invoked his Fifth Amendment rights against self-incrimination.
The prosecution objected and the jury was sent out. Following arguments by both attorneys about the question, Judge Belvin Perry ruled that he would instruct them to disregard that Jordan took the Fifth.
On Monday, Casey Anthony's attorneys asked the judge to select a new jury. The attorneys sought the mistrial based on a ruling by a federal judge in Miami last week that declared Florida's death penalty unconstitutional.
Anthony has pleaded not guilty to first-degree murder and could face the death penalty if convicted of that charge.