cross-examine
verb [ T ]
LAW uk/ˌkrɒsɪɡˈzæmɪn/ usto ask someone detailed questions, especially in a law court, in order to discover if what they said earlier was true:
Expert witnesses were cross-examined on their statements about how the accident had occurred.
cross-examination
noun [ C or U ]
Under cross-examination the witness admitted that she had been lying.