Fawcett's Finest: Mighty Mental Men

Pep Pepper was known as the International Policeman, Radar, and had a notable career protecting various lands on Earth-S attacked by the threat of budding Cold War influences following World War II. Around the same time, Kylar was the magnanimous ruler of Mars-S, who protected his people from various treats aided by Captain Marvel Junior. Unlike the Martians of Earth-One, those of Earths Two and S possessed no natural powers of their own.

Radar was an ally of the original older Captain Marvel.  The son of circus performers, Radar inherited unusual strength and mental aptitudes including telepathy and a radar sense. After initially being a performer, Pep's encounter with Captain Marvel ended up leading him to be a telepathic detective with amazing abilities. 

Another policeman on Earth-One was John Jones, who originated from the planet Mars, who patroled Middletown with police partner Officer Saunders. While actually J'Onn J'Onzz aka the Martian Manhunter displayed superhuman physique and mental powers of his own, as Jones he was more subdued and hence relied primarily on his alter ego. 

Assuming the identity of international playboy Marco Xavier, the Manhunter traveled up and down the French Riviera seeking to circumvent the criminal chaos originating from the sinister VULTURE organization and its mysterious leader, Mister V aka Faceless. J'Onn eventually defeated Faceless, who was the original Marco Xavier. 

And the human Marco Xavier was the  Earth-One twin of Earth-Two's British secret agent Richard Spencer, a member of the elite Espionage organization. Presumed killed in a plane crash, Spencer adopted the alter ego of Black X, or Black Ace, and battled various threats around the world.

Police officer Larry Jimmy Trent worked alongside his partner Sandy Keane as the "Radio Patrol", capturing various unusual criminals in New York City during the early 1940's on Earth-Two. Possessing a peak physique and intuitive investigative skills, Officer Trent even brought a young Alexie Luther to justice, shortly before that villain met his arch-foe Superman.

Trent was inspired towards this crimefighting career due to the influence of Superman, who saved him from a suicide attempt. Larry had previously been a professional boxer until a corrupt manager ended his career, and the Man of Steel impersonated Trent in order to restore his reputation. Once this was accomplished, Larry decided to pursue a new life, like that of another superstrong alien officer in John Jones and a telepathic physically fit policeman in Pep Pepper.

Another human inspired by an alien avenger was wealthy playboy Dirk Giles, who sought to attract the attention of the girl he loved Hazel. Although she had no feelings for Giles, she was an avid fan of the Martian Manhunter, and so Dirk hatched a scheme whereby he disguised himself as the hero. After a series of feats that replicated some of the abilities of the Manhunter of Mars, he encountered the real alien atlas who attempted to ascertain the motivation for the impersonation.

However, both J'Onn and Dirk also attracted the attention of a gang set on defeating the resident hero(es), although the pair worked side-by-side to defeat the crooks instead. Hazel did indeed fall in love with Giles, although she made him swear to give up his caped crusader career once and for all.

These two Manhunters, J'Onn/John and Dirk, matched the heroism of Earth-Two's Roh Kar and Larry as well as Kylar and Radar of Earth-S. While Dirk/Martian Manhunter and Roh Kar/Manhunter of Mars were one-hit wonders, their counterparts Larry Trent and John Jones/J’onn Jon’zz had lengthy careers in crime fighting as both licensed lawmen and caped crusaders.