Almost perfect save for one big thing... the end (Spoiler).
This movie was truly well written for the most part but got very lazy in how Leland die. Or more clearly how Allen (Chris Klein) killed Leland. Here is why, in order for Allen to have plan this he would have had to know that he would be put in the same facility as Leland (which is probable), know that he could get a knife (which is impossible and in the movie don't even attempt to explain it just that it came from Pearls lunch), lastly that Leland would be out in the yard at the same time that he is in the yard (which at best could only be a fluke since this was the first time Leland was allow out in the yard since being there and was only happened because it was a favor to Pearl done by one of the Jail personal).
Now, the fact that Allen all together didn't have enough motive to give up his life by killing Leland, unless he too was psychological mess up (such as Leland, Becky, and to some point Julie). If you observed him from the beginning of the movie you soon understand why this is opposite to his character, which up to when was stable, supportive, kind, and very mature. And the fact that his mother died a year ago and he still was that level headed makes it even harder to believe that he'd just snapped, And even when does "snap" and commits the robbery (they even make it a point to show how) he is polite saying "excuse me" when a woman runs into him and "thanks you" after the man gave him the money. What with this intentional contradiction?
I wish that they could have work out a better way because except for these issues the movie was touching and emotionally grabbing. So when this happens it take you out of the emotional soup that your in and reminds you, "oh yeah, it's only a movie"... so sad. I still gave this movie a 8 out of 10 but like this: the first 80% of the movie got ten out of ten and the last 20% got 5 out of ten. It would have been zero but aside for those issues the end was actually great too. Please don't be careless with such beautiful work, it is a shame to have done everything so great and not put the finishing touches on it. It's cake without the frosting, a Sundae without the fudge, a the plot without the climax.