Investigators grew suspicious after Roberto Sol Cabrera Zavaleta , 38 , became `` markedly nervous '' when asked what he was transporting , Mexico 's Public Safety Department said . Police say the man was carrying 18 monkeys in a belt under his shirt . Authorities say they grew suspicious when Cabrera was nervous during questioning . Comment:
Police say the man was carrying 18 monkeys in a belt under his shirt . Authorities say they grew suspicious when Cabrera was nervous during questioning . Comment: