So apparently there was a TV movie aired on CBS in 1984 called W*A*L*T*E*R. It was a M*A*S*H spinoff which chronicled the post-Korean War adventures of-- oh yes-- Corporal Walter "Radar" O'Reilly. Long story short: he moves to St. Louis and becomes a cop.
Originally intended as a series pilot, it was never picked up. But, honestly, is that surprising to anyone? I am saying this as a M*A*S*H fan. Radar is my favorite character on a series full of great characters, but his appeal is his boyish naivete. The first time he finds a decapitated hooker in a dumpster, it's all over. Nobody wants to see that.