My first thought was that we indeed have come a long way in 50 years. There was not a lot of emphasis at all on battered wife syndrome, post partum depression, and other situations that might be associated with the commission of a murder.
Clearly, the woman did kill her husband. The findings now are that there may have been mitigating circumstances. That's very sad. It's too bad that she couldn't go to the proper authorities at the time to complain: such things would no doubt be taken more seriously today.
My general observation about the justice system is that we are getting increasingly more sophisticated today. Not that some people cannot be wrongfully accused: but with DNA testing, sophisticated forensics, and other technology, I believe we're going to be able to prove murder with more reliablity than we did in the past.
On the flip side, I just saw a documentary recently about a man who brutally murdered his fiance in the US. The unbelievable catch was that there was an eye witness (an ex-girlfriend) who actually shot photos of it. The ex-girlfried agreed to testify in a plea bargain, but she was not a credible witness due to her demeanor. The jury found the guy not guilty after just a few hours of deliberation. A few years later, when the guys home was sold, construction workers found an unusual stash under the floor in one of the rooms. Sure enough, it was the photos of the brutal rape and murder of the young woman, just as the witness had testified.
The guy apparently served a few years for perjury, but not for murder. He proudly said, "Of course I did it." But, due to double jeopary laws in the US, he'll never be tried for it.
The door swings both ways...