Various thoughts *SPOILER*
How sure was the defense attorney that he had identified the murderer? It would seem that he took one gigantic risk, based on evidence as circumstantial as what was about to convict his client. I guess he had nothing to lose but if his tactic had failed he would have sealed a guilty verdict for his client even more surely than what looked already the case.
Personally I think it's pathetic when defense attorneys do the police's work for them. :-) And at the end of it, does his father say, "Thank heavens you did what you did or we'd have convicted an innocent man!"? No, he just tells his son to buy him a drink! It begs credibility that defense attorneys could be so detached from their clients and consider it beneath their dignity to actually make contact with the guy they're supposedly trying to save from the gallows.
As for the accused's retort "Haven't you ever given sweets to children?", as a rhetorical question I think it was 100% legitimate as an answer to the prosecutor's loaded question. Thankfully the judge told the jury to disregard the question and its answer.
Cathy O'Donnell, in my opinion one of the most beautiful actresses of that era, is perfect as the loving and loyal wife, similar to her roles in Detective Story and The Best Years of Our Lives.