My first memory of him in a film was Pvt. Mike McHugh... 
in Sands of Iwo Jima saying, "Tough sergeants just roll off my knife," then he flubs grenade tossing and later is shown dead on the beach with They Were Young and Gay in the pocket of his blouse.
BTW The film came out in 1949 so it must have been from a later viewing because as smart as I was at age two, I was not that smart--
He played a perpetual juvenile for many years up until his role as Tod Stiles... 
in "Route 66" that was a favorite of mine and my late Father's.
His seven year stint as Officer Pete Malloy in Jack Webb's "Adam-12" TV Series was his longest role but he was always cast in many film and television parts.
I auditioned for a part in "Adam-12" the last year of the series and got to meet him as he walked by with his co-star Kent McCord. Then six year later I was on the set of a "Fantasy island" he was in but I did not get to speak to him.
I once saw him as I pulled up to a traffic light about the same time in LA. I waved and he waved back but I'm sure he was just being polite.
Even in 1981, he did not look 40 year old. He and Dick Clark must have drank from the same well as they never seem to age--
God Bless, Marty. Rest in peace.
http://community.fortunecity.ws/lavendar/strangelove/2/iwojima12.jpg
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