From Headquarters(1933)

SEE...The Miracles of Science the "lab" blood test x-ray and ultra-violet ray track down a murderer!

A wealthy Broadway playboy is found dead, and it comes to light that he was a vicious blackmailer. It's up to police lieutenant Jim Stevens to pick the murderer out of several likely candidates. Meanwhile, Stevens embarks on a torrid affair with Lou Ann Winton, who may or may not be involved.