As the Paramountain fades into the credits, a disturbing music theme underscores the credits. It's a good riff, but clearly at odds with the mood of the opening.
Hal Skelly is Sergeant Dan Malone (Irish cop, now that's original) walking the beat in some downtown. A horsedrawn milk wagon goes by. At a police call box, Malone relates his handling of disturbances to headquarters. Caught the kid that stole the milk, made him return it, then stole a quart for him 'cause "he was thirsty". His sidekick, Watts, played by William B. Davidson, expounds his theory that juvenile crime is exacerbated by unsupervised hangouts. Malone is stepping on cracks in the sidewalk like some hopscotch participant. Director Wellman keeps the action flowing, dollying his camera around a corner and down the street. [This was "Wild Bill's" 3rd talkie for 1929] A fight is quelled by Malone bonking the two guys heads together then kicking them in the pants. He is carefree.
A fellow officer tells Malone he just caught his brother, and Eddie Evans, drunk and up to no good. Now, an astute viewer might have glanced at the credits and noticed the source material is Edwin Burke's "Brothers", and thereby be forewarned. Dan goes upstairs and engages in playful banter with his mother. Watts goes to Eddie Evans' parents. A firey Evelyn Brent, playing (Kitty), Eddie's defensive sister, springs at Watts. She starts hot and is just warming up. Each family blames the other, and a life changing moment will send Malone into a get tough on crime mode. With each turn of the script's page, the drama grows grimmer.
As Malone's get tough policy gains him promotions, the liability of his brother weighs heavier upon him. A woman's wrath will spring the 'Woman Trap'. When the last reel unspools, the wide open mood of the first has steadily closed in to the point of claustrophobia. Malone has morphed into someone else.
I found the conclusion personally unsatisfying. The music under the opening credits fits here. But if you ever wondered about Hal Skelly's acting chops, they're all here.