Three ex-cons have been convicted of committing separate violent bank robberies and the last of them is on death row with only 9 days left to go. The local public defender has doubts about their convictions - largely on the basis of fingerprint evidence, so he enlists "Charlie Chan" to investigate. Mantan Moreland "Birmingham Brown" and Benson Fong "Tommy - No. 3 son - Chan" chip in well as our Oriental sleuth uses his fiendishly clever deductive mind to prove the fingerprints are a forgery and to reveal the true perpetrators. This is a fun, quick-moving little crime caper done on a pretty…