Red has an ability to deliver contraband of almost any type (except, on his own principles, hard drugs and weapons) into Shawshank. This makes him an important man within the prison's social structure — and it is also the reason that he first becomes acquainted with Andy. Red said he was the only guilty man in Shawshank because he murdered his wife for insurance money by cutting the brakes on her car.
He would inadvertantly murder three more when his wife picked up some passengers on the way into town, resulting in Red getting caught. Red stated that he only did it because he was "a young, stupid kid" and that not a day goes by where he doesn't feel regret for the terrible crime, and it is speaking from his heart like this that resulted in him getting paroled after serving forty years out of a life sentence.
As both Red and Andy's sentences drag on, the two become closer. Once Andy breaks out of prison, he gives Red directions to find a large sum of money with the instructions to come and find him in Mexico. He follows his instructions and both of them embrace, when they meet each other again.