It was very loosely based on the real story of Ma Barker, who is depicted as a corrupt, mentally-disturbed mother who encourages and organizes the criminality of her four adult sons in Depression-era southern United States.

[4] In rural Arkansas during the Depression, middle-aged Kate 'Ma' Barker, disturbed by the childhood incestuous rape she experienced at the hands of her father and brothers, also brutalizes those around her, while indulging in her monstrous sexual appetites.

When Herman and Fred are arrested and imprisoned for petty theft charges, Ma leads Arthur and Lloyd on a bank robbery spree for the money to free her sons from jail.

At the climax, a large contingent of FBI agents and local police arrive at the Barkers' hideout and a huge shootout ensues between the authorities and the surviving members of the gang.

[8] Howard Thompson of The New York Times wrote that "Miss Winters is plain wonderful" in the film, which although similar to Bonnie and Clyde in subject matter, "happens to be more honest and less pretentious, with no grudging admiration for criminal 'rebels.'

What hoists the picture into real substance toward the home stretch is an eerie and fascinating by [sic] credible sequence with the Barker clan holding as captive a blindfolded millionaire, strongly played by Pat Hingle.

"[9] Peter Schjeldahl, also writing for The New York Times, described the film favorably as a "low budget, unpretentious, extraordinarily brutal little movie about the pathology of 'senseless' murder.

"[10] Arthur D. Murphy of Variety wrote, "Corman's production has the naturalistic look sought, but the occasionally poor looping and uneven color and textural qualities add up to a liability.

"[11] Gene Siskel of the Chicago Tribune gave the film 1 star out of 4 and called it "92 minutes of sado-masochism, incest, satyrism and voyeurism woven into a disgraceful screenplay ...

"[12] Charles Champlin of the Los Angeles Times stated, "It is such a close if mocking tribute to a celebrated movie of a couple of years ago that it could be subtitled 'Mommie and Clyde.'

"[13] Kenneth Turan of The Washington Post wrote, "Its lyrical pastel shades—even the blood blends deftly into the color scheme—show that infinite pains have been taken with the film's visual aspect, a Corman trademark.