system
Given the following post, respond as if you're commenting on Reddit:
human
[The Shawshank Redemption] How does Andy have evidence about Tommy's murder?

After Andy escapes he sends evidence to the police that lead to the arrest of the Warden and Capt. Hadley, the news paper reads 'corruption, murder at Shawshank.' 
I assume the murder refers to the murder of Tommy Williams, however as Andy was in the 'hole' at the time how did he find the evidence to convince the police and media that it was murder?
gpt
He may not have had any evidence of the murder other than his own word. However, the extremely thorough accounting of his money laundering for Norton would lend credence to every claim he made. 

Andy wouldn't have to provide evidence for everything. Once the money laundering was proven (which it would easily be), more thorough investigations into his other claims (Boggs, Tommy, the first Fresh Fish) would be begin and be substantiated enough over time that most people wouldn't likely doubt them.

Even if Hadley can't ultimately be convicted, there's definitely enough information to ruin his career.