Scott Calibrax’s review published on Letterboxd:
Leaving aside the great crime/noir pictures that featured A-List stars (Bogart, Hayworth, Mitchum, etc.), Side Street is one of the best of the next tier down (or maybe it's the tier below that?). It's also one of the best of the straight crime films that does not revolve around a femme fatale. The gritty and efficient story that follows the mistakes of a broke part-time mail carrier who steals from the wrong people wastes no time on bullshit-- it's all suspense and blackmail and cat-and-mouse and car chases and shots of liquor with beer chasers and beatings, shootings and stranglings from about the 5-minute mark. Unlike the other well-known noir starring Granger and O'Donnell, They Live by Night, Side Street does not get bogged down in a sappy love story. The focus here is on the mechanics of the crime plot.
The cinematography and location shooting is stunning-- tons of striking compositions and uncommon framing and angles. There's a brilliant car chase that's captured from thirty stories up in some shots.
Essential if you are into crime films from the 40s & 50s.