Not to mention official and unofficial benefits; health care and a police pension obviously, but also running drugs on the side, free prostitutes, bribes, immunity from other police, and near absolute power over other individuals in the regular course of your job.
Even then, in 1988, that $70,000 salary was pretty good. That's the equivalent of $149,000 today. (Or $52,000 in 1981 when he was a cop).