Welcome back, amigo. The description of Columbo's life, as reconstructed from the many little clues dropped throughout the episodes, is in the Scrapbook area of this site. The link says "Columbo Chronology: A Biography of Columbo".

Th info about the real-life retirement age for LAPD was posted here on the Forum, a couple of years ago. I'm afraid I don't recall who posted it.

Thanks, Ted! I wonder how come I didn't find that section about Columbo Chronology in the Scrapbook. As for the other question, well, bad luck!