That is the reason you need to be able to kill a man who needs killing.
As an example, there was the guy in Oklahoma a few years ago who had terrorised an entire town, but they couldn't make any realy serious case against him and no one was willing to testify to put him away for only a few years and face him when he came back.
Someone killed him.
On the main street of town.
No one saw a thing.
After years, no one still has seen a thing.
There are a lot of occasions when the law is inadequate.
What Ms. Harris needed was an "A" list atty. Houston has probably the top criminal bar in the country, on both sides. Her "B" list Atty was eaten alive by the prosecutor.
Don't forget that Clara was his second wife!
She and he should rightly have been dead years ago, by your reasoning.
They should have been killed by his first wife back when Clara was the "other woman."
I think the only crime that got him killed was failing to handle her EGO gingerly enough when he left.
This was an "honor killing" and last I heard, we don't do that here in America. I can see letting people off for killing the person that rapes them or their loved ones, or killing someone who murdered someone, etc...
But Clara didn't avenge something he did to her, he avenged something he wouldn't do for her -- stay faithful.
The motives for her vengence were petty and selfish. I know it hurts, but it just doesn't justify murder.
Adultery is too common to justify murder.