Witness

sent Melanie Bush and Sabalom Glitz to Space Station Zenobia to act as witnesses in the Sixth Doctor's trial. (TV: The Ultimate Foe)

Leela, K9 Mark I (who also spoke for K9 Mark II), Narvin and Torvald were witnesses at the inquiry into Romana II's actions on Gryben. (AUDIO: The Inquiry)

Other contexts
During the Year That Never Was, deemed that the Tenth Doctor should be a witness for when he killed Martha Jones. (TV: Lat of the Time Lords)

Davros intended for the Doctor and the Children of Time to witness the detonation of the Reality bomb. (TV: Journey's End)