Yeah in the 90s Grisham was being adapted into a big movie every year. I didn’t even realize that he was still publishing until I looked it up just now.

A Time For Mercy spoilers from Wikipedia

Once again, Brigance is the court-appointed lawyer who seeks truth and justice for his client, in this case a sixteen-year-old boy named Drew Gamble, who is charged with murdering a law enforcement officer and faces the death penalty. As Jake digs into the details of the case, he knows he has to find a way to save the boy, even at the risk of his career and his family’s safety.
............
After Josie, along with her 14-year-old daughter Kiera and Drew, moved in with Kofer, the deputy subjected them to domestic violence while drunk. Since Kofer performed well when he was sober and was well-liked by his fellow officers, no reports were filed and Sheriff Ozzie Walls was unaware of Kofer’s behavior. On the night of the murder, Kofer knocked Josie unconscious while breaking her jaw. Assuming his mother was dead, Drew called 911 to report the situation before using Kofer’s service pistol to shoot the deputy in the head.......
Jake puts together a case he hopes will sway at least some jurors to find Drew not guilty. The strategy is based on the fact that Kiera is pregnant after being sexually assaulted by Kofer. By concealing the pregnancy until the trial, the element of surprise does indeed have the desired effect, resulting in a hung jury and Drew’s release on bail.

This summary doesn’t make the story sound offensive, but the mercy is still for the person who [justifiably? or just understandably?] killed a bad guy. It still sounds like a revenge killing, and not self defense, based on the described legal defense. The level of duress and proximity to the crime sound more sympathetic than A Time To Kill. But it doesn’t sound like a corrective. If it gets made into a movie I’d probably be willing to stream it.