Heemeyer equipped an old bulldozer with three television cameras and monitors so he could see to steer.
He needed the television cameras because of a bad back.
( z1 need :ARG0 ( z2 he ) :ARG1 ( z3 camera :mod ( z4 television ) ) :ARG1-of ( z5 cause :ARG0 ( z6 back :ARG1-of ( z7 bad ) ) ) )