Watching "A Killer is Loose" it's not hard to see how Budd Boetticher garnered a reputation as one of the top B movie directors. With the limited resources allotted to the makers of B movies, not to mention the casting of often second rate actors, a lot of skill went into creating the few B movies which have endured.
Boetticher gets good performances from leads Joseph Cotton and Wendell Corey (not strictly B movie actors) as well a surprisingly convincing Rhonda Fleming. The work of veteran cinematographer Lucien Ballard contributes much to the success of this taut, well written thriller.
While not a classic, its remains a fine example of its genre and worth a look.