John Larkin

Career overview

Subject: John Larkin (Writing/Actor).
Goal: 180-260 word career overview.
Format: 2-3 short paragraphs, plain prose, no markdown, no headings, no preamble.
Constraint: Use ONLY provided facts. No inventions.
Note: The prompt asks for a career overview of "John Larkin (Writing)", but the sources mostly describe him as an actor. Source [1] lists "Known For: Writing" and "Known Credits: 16". Source [2], [3], [4], and [5] describe him as an actor. I must stick to the facts provided.
Source [1]: John Larkin (Writing). Known credits: 16. Birthday: November 30, 1901. Death: January 6, 1965 (63 years old). Birthplace: New York, New York. Also known as John Francis L.
Source [2]: John Larkin (actor, born 1912). Career: nearly 30 years. Portrayed Perry Mason (radio) and Mike Karr (television daytime drama The Edge of Night) in the 1950s. Born April 11, 1912. Died January 29, 1965.
Source [3]: John Larkin (actor). Born April 11, 1912, in Oakland, California. Known for Those Calloways (1965), The Dick Powell Theatre (1961), and Saints and Sinners (1962). Married to Audrey Larkin, Teri Keane, Sibyl Genelle Gibbs, and Helen Adele Sweeney. Died January 29, 1965, in Studio City, California.
Source [4]: American actor. Nearly 30-year career. Portrayed Perry Mason (radio) and Mike Karr (television daytime drama The Edge of Night) in the 1950s. Acted in an estimated 7,500 dramatic shows on radio.
Source [5]: Actor Guide for John Larkin.
Source [6]: Irrelevant (mentions Maryellen Larkin's grandfather, but doesn't explicitly confirm John Larkin is the grandfather, though it's implied. However, I should be careful. Actually, Source [6] says "Maryellen Larkin's grandfather" in relation to Paul Linke working with Ritter. It doesn't explicitly state John Larkin is the grandfather. I will omit this to be safe).
Conflict Check: Source [1] says born Nov 30, 1901, in NY. Source [2] and [3] say born April 11, 1912, in Oakland, CA. Source [1] says died Jan 6, 1965. Source [2] and [3] say died Jan 29, 1965, in Studio City.
Decision: Since I am writing a career overview, I will present the information available. If there are conflicting biographical details, I will focus on the career aspects which are consistent.
Paragraph 1: Career Summary.
John Larkin was an American actor with a career spanning nearly 30 years. He is recognized for his work in the 1950s, where he portrayed two fictional criminal attorneys. These roles included playing Perry Mason on radio and Mike Karr on the television daytime drama The Edge of Night. His extensive work in radio included an estimated 7,500 dramatic shows.
Paragraph 2: Credits and Personal Details.
Larkin is known for his involvement in productions such as The Dick Powell Theatre in 1961, Saints and Sinners in 1962, and Those Calloways in 1965. Biographical records provide varying details regarding his life. One source lists him as a writer with 16 known credits. Other records identify him as an actor born on April 11, 1912, in Oakland, California