John Maddox Roberts is both a science fiction and mystery author with a knowledge of ancient Rome as well as Catholicism. Several of his SF novels – Cestus Dei combines SF, ancient Roman culture, and the Catholic church into an adverture yarn.

His SF work aside, Roberts has written two mystery series. A three-novel set feature Gabe Treloar and is set in contemporary times. The second, and more extensive series is set in ancient Rome, just as the Republic was ending and Julius Cæsar was rising and feature Decius Cæcilius Metellus the Younger, the something of a ne'er do well son of – you guessed it – Decius Cæcilius Metellus the Elder.

Decius has a talent for solving mysteries and is called on in different circumstances to solve murders.

Roberts' obvious expertise in Roman history lends extraordinary life into the novels, detailing everything from what the typical Roman nobleman ate for breakfast to how ancient "boxing gloves" were worn and used. They had metal spikes – ouch.