Black Friday (1940).

Complications ensue when a criminal's brain is transplanted into a professor. Boris Karloff and Bela Lugosi star, and Curt Siodmak (brother of The Spiral Staircase's Robert Siodmak) is one of the screenwriters.

MacDonald x 2: "The Fatal Impulse" (1960).

In this November 1960 episode of Boris Karloff's Thriller TV series, someone bent on political assassination places a bomb in a woman's purse, but the police are hot on the trail. Featuring Robert Lansing, Elisha Cook Jr., and Mary Tyler Moore, it is adapted by author-screenwriter Philip MacDonald (The List of Adrian Messenger, etc.) from the novella "The Impulse" by John D. MacDonald (Cape Fear, etc.) that appeared in the June 1955 issue of Cosmopolitan.

Mystery-related Hirschfeld cartoons.

Truman Capote in Murder by Death

The Web site of the Al Hirschfeld Foundation features online images of the renowned cartoonist's work that reflect the entire span of his long career. Although the resource is a work in progress, those images with a mystery connection include Arsenic and Old Lace (with Boris Karloff, 1941), Basil Rathbone (as Sherlock Holmes, 1990, and in Witness for the Prosecution, 1957), The Bishop Murder Case (1929–30), Dial M for Murder (with Maurice Evans, 1953), Everett Sloane in Crime Doctor (1944), Florence Reed in The Shanghai Gesture (1928), Murder by Death (1976), and A Pin to See the Peepshow (1953).

This is only a test.

This podcast from LA Theatre Works partially deals with the personalities who recorded public service announcements for CONELRAD (the precursor to the Emergency Broadcast System), including Johnny Cash and Boris Karloff. More CONELRAD-related materials are here, including CONELRAD 100: Atomic Film.

About the image: Bert the Turtle from the civil defense film Duck and Cover (dir. Anthony Rizzo, 1951).