Following Tapper's 1980 exhibition The Law and It's People his legal series has become increasingly popular and sought-after. The series commenced with a commission received from the Auckland Law Society commemorating its centennial year. The Llb's, a stylish work, features four Auckland University law graduates in cap and gowns, about to make their mark on the world.

During this period Tapper produced his largest lithograph, The Crown Prosecutor. Pleased with the finished work, the artist says: Although its image was sketchily drawn, it was nevertheless full of the incidental of courtroom drama; beautifully drawn, without any hesitation.