You search him.
This spring, somewhere in Scotland, police were faced with that situation during what, theoretically, was a "consensual" stop and search.
In 2013-14, a major new report from the Scottish Policy Authority has found, there were 223 searches of children under 10, three-quarters supposedly with the permission of the subject.
Wayne Mawson, the assistant chief constable responsible for such policy, said he was not convinced it made sense to talk about obtaining consent from young children.
"Probably we should be searching legislatively with really young children."
Older children and teenagers accounted for more than one-third of all stop-and-searches.