The series starred Richard Carlyle originally as the title role of Jack "Flashgun" Casey.

The series co-starred actress Jan Miner as Ann Williams, Jack's girlfriend and a fellow reporter.

In 1934, author George Harmon Coxe who was already known for the writer of Black Mask magazine, which was launched in 1920,[1] created a new character called Jack Casey who solved crimes for the police.

[2] The character was so successful in the magazine that Coxe wrote a novel about him called Silent Are the Dead in 1942.

Richard Carlyle portrayed the title role of Jack Casey, nicknamed “Flashgun” for the first five episodes, but was replaced by Darren McGavin for the rest of the series.

Casey is a reporter, specifically a photographer, for the fictional newspaper, The Morning Express in New York.

His girlfriend, Ann Williams, which was played by future Palmolive spokesperson and actress Jan Miner for the entire series, is also a reporter at The Express.

In June 1951, along with Carlyle, Gibson was replaced by Cliff Hall who entered season two playing the role of Ethelbert.

[6] Jan Miner maintained her role as Casey's girlfriend and fellow Express reporter, Ann Williams.