Behavior specialists in Aruba are questioning the Dutch suspect being held in the disappearance of Alabama honors students Natalee Holloway.
A police spokeswoman says the specialists from Holland want to observe Joran van der Sloot's body language.
They're also looking for inconsistencies in his account of what happened the night Holloway disappeared in May. The 17-year-old has already changed his version of the events at least once.
A police spokeswoman also says authorities are searching for a pair of white tennis shoes van der Sloot apparently lost the day Holloway vanished. But she isn't saying why.
Meanwhile, volunteers are conducting a final search of a landfill where a witness claims to have seen men dumping a female body. The head of the volunteer search group says they will leave Wednesday unless they find something significant Tuesday.