Before and After has a plot (if you could call it that) with no twists: A sixteen-year old boy, Jacob Ryan (Edward Furlong), is accused of murder. The rest of his family (played by Meryl Streep, Julia Weldon, and Liam Neeson) is torn between telling the truth and risking the Jury not believing their son, or lie and live with those lies the rest of their lives.
The acting is pretty good---I thought everyone was convincing in their roles (especially Furlong in what I think is a difficult role). However, no amount of acting could convince me that this the plot (even in reality) is anything more than trivial. Murders happen. People die. And most people, especially those with money, get away with very little of the drama we see in the movie.
The surface lesson we learn seems to be that telling the truth is the way to go. However, I think the movie is a statement about truth (or lack thereof) in current society, and the system of justice. Just think: what would it cost you to to correct every lie that you've made? I think humans, as a society, are chronic liars. It is not surprising that our justice system is hardened towards this, and even when the truth is told, it will always be greeted with skepticism.