Just watched Prescription Murder again 2 days ago.

I like the episode a lot, but I didn't like the continued slurred speech patterns of Columbo with the cigar in his mouth.

Of course the character really hadn't developed yet, although the plot formula was almost as good as any.

I agree and I think the character seemed to grow right before our eyes when he gave Miss Hudson that "You'll be followed . . .and you'll be hounded" speech.

That was a great scene. "You seem worried, Miss Hudson. Whatsamatter, you've never seen a pair of sunglasses before?"

any of thejack Cassidy , Robert Culp or patrick Mc Goohan movies, would be a great start

I think Columbo's character is quite
well developed in "Prescription Murder".
Peter Falk already had the role down
when he did it, and he kept it up faithfully for several seasons (i.e. his
"modest, mildly eccentric" persona) until
"Last Salute to the Commodore", which as others point out is a very poor episode, and the one in which Peter Falk decided to change the role to "arrogant and goofy" which he was in many, but not all, of the remaining episodes of the original 1970's series.

i personally really like Lovely but Lethal, but i can and do watch them all over and over all the time.