From The Perry Mason TV Show Book
Gossip columnist Danny Shine has a reputation for ruining reputations. Consequently, Danny's enemies greatly outnumber his friends. So it could have been one of many that rubbed him out.

Cloris Leachman plays Gloria, and you'll see Gary Collins and The Munster's Pat Priest.
February 1, 2021 - MeTV showed this episode at 11:30 tonight, out of order, as a tribute to Ms. Leachman, who had just passed away (on January 27th) at the age of 95. OLEF641

[Edited to entirely remove second paragraph and rewrite the Leachman-Collins sentence. Previous content misidentified defendant and contained MAJOR spoilers to the ending. Just watched this episode for the first time and wished very much I had not read the previous version of the summary.]

ed. belatedly... spoilers are allowed and welcomed! But this banner must be displayed (see discussion about Spoilers at the About This Wiki page.

Spoiler Warning! Do Not Read Below If You Have Not Seen The Episode

Alex Tanner has an ironclad alibi to excuse himself as a suspect; his baby has been kidnapped. The only problem is that there really is no baby except in the mind of his half-crazed wife, and Alex is hiding a very big and very ugly secret.

An interesting example of misdirection and unreliable narrative on TV.