Eric Linden (Corporal Greg Carroll), Ben Alexander (Sergeant Paul), Donald Curtis (Lieutenant John Harmon), Ann Doran (Linda), Constance Worth (Alma Barton), Boyd Irwin (Colonel Longstreet), George Lynn (Professor Carroll), Weldon Heyburn (Sergeant Blake), Robert Frazer (Captain Bryant), I. Stanford Jolley (Carl Flegler), Dudley Dickerson (Sam), Bernice Pilot (Mamie), Ray Erlenborn (Private Norton), Dennis Moore (Stanley Hume), Earle Hodgins (Wallace, military intelligence), William Ruhl (Captain Gray), Emmett Vogan (Harold), Jack Cheatham (Martin, military intelligence), Bill Cartledge (elevator operator). Director: Joseph H. LEWIS. Screenplay: Edward Bennett. Story: Arthur Hoerl. Film editor: Howard Dillinger. Photography: Arthur Martinelli. Wardrobe supervisor: Emanuel Glussman. Production manager: Earl Sheffer. Assistant director: William Strohbach. Sound recording: Ben Winkler, Arthur B. Smith. Producer: E.B. Derr. Executive producer: George R. Batcheller.Copyright 13 June 1941 by Producers Releasing Corp. No recorded New York opening. U.S. release: 27 June 1941. 7 reels. 70 minutes. Alternative title: ARMY MYSTERY. SYNOPSIS: Spies infiltrate an army base. Suspicion falls on a young corporal, though anyone with half a brain (except, of course, the deadheads in army intelligence) would realize that he was the least likely person in the entire camp.COMMENT: Ingeniously directed by Joseph H. Lewis to pad out a meager budget by actually shooting both outside and inside the studio sound stages, this PRC effort emerges as a reasonably captivating little thriller, helped out by some attractive performers, not least of which is Eric Linden who turns in a much classier job here as the principal hero than he did as Norman Foster's helpmate in "Ladies Crave Excitement". Both heroine Ann Doran and sultry heavy Constance Worth also appeal, while Dudley Dickerson and Bernice Pilot provide some fair comic relief.

CRIMINALS WITHIN is another forgettable and worthless crime thriller from an era full of such films. It seems like producers didn't let a lack of money or talent put them off churning out B-picture after B-picture and this one is particularly devoid of enthusiasm. The hero is the brother of a mad scientist who gets killed by enemy spies. The hero decides to go hunting the spy ring himself but nefarious elements within the army are working against him. It sounds like it could get thrilling but it never is, going through all of the elements with a distinct lack of relish and featuring below par performances throughout. It's a real dud.

It's one thing to go for laughs and have a comedy team being incompetent while going through basic training, but with a war looming over the United States, writers were very irresponsible in creating the part played by eternal juvenile Eric Linden. Not only does his incompetence get valued papers stolen, but a bunch of scientists (including his own brother) and the spy girl he loves killed. It's all over new explosives, apparently so powerful and deadly that spies will forgo creating their own. Blonde vixen canteen hostess Constance Worth is obviously no good and even when he escapes her (after breaking out of the brig), he gets hooked up with nosy reporter Ann Doran. Even with all the intrigue, I just found this an insipid, unbelievable story. Someone like Linden would be busy peeling potatoes for sure rather than working as a file clerk for a commanding officer. There have been plenty of spy movies where the good guys made boo-boo's, but they were always fixable and never threatened the entire security of the country. It's obvious that Linden will dig himself out somehow, and that's the unkindest cut of all. If this didn't have a cast of American actors, I'd think that this was made on the sly by the enemy to be anti-American propaganda.

Joseph Lewis, later renowned for lifting standards above what might be expected for the second features that he was generally given to direct, through adept management of his actors as well as skillful editing, simply goes through the motions here with a low-budget PRC film that is completed in 1941, before formal entry of the United States into World War II, and it is a carelessly written espionage tale akin to pulp fiction of its day, with scant cinematic substance and ragged production values. When Professor Carroll, a U.S. Army scientist is murdered after formulating a powerful chemical explosive, Military Intelligence assumes the criminal investigation, leading to an apparent foreign spy ring that, along with M.I., is seeking to forestall inquiries being made by Carroll's younger brother, Army Corporal Greg (Eric Linden) whose aim (while AWOL) of locating his sibling's killer interferes with his pursuers as Greg is known to have had in his possession a list of other researchers involved in the development of the explosive who are, therefore, in danger. Greg's slapdash antics while escaping from his Post stockade and from military investigators, as well as from a contingent of spies, are entertaining only to him but Linda (Ann Doran), a reporter, takes an interest in Corporal Carroll because she needs more information from him in order to complete and file a news story about the affair, and the two are presently in trouble from all sides, especially from a diverse collection of alien agents, all seemingly as American as apple pie. This is a disappointing effort with often startlingly trite dialogue that renders ineffective any attempts by the players to create believable roles, and spirit is missing from a narrative within which nothing results from anything. However, there are veteran troupers on board here who give better service than their assigned lines deserve. A scene stealing comedic Negro couple, played by Dudley Dickerson and Bernice Pilot, give nicely natural performances, while acting honours go to Doran, whom fate has determined will be underrated, as she gives life to her part, and it is pleasant to watch Dennis Moore, although in a small part; capable Donald Curtis is trounced by his largely silly lines and Constance Worth appears to be playing to a mirror in a film that moves briskly but includes precious few sequences that will be of any interest to most viewers.