Here is an excerpt from Jessie Misskelley, Sr.'s testimony at Jessie, Jr.'s trial:
Q: Do you remember having a conversation with little Jessie and Officer Allen about the reward money?
A: Yes, sir.
Q: Do you remember what the nature of that conversation was?
A: Mike Allen was, and Jessie was joking about the, he said, forty thousand dollar reward. He said if Jessie, if they get a conviction out of this that Jessie would get the forty thousand dollar reward and he's gonna buy him a new truck. And Jessie's laughing and said "No I'm not either." He said "I'm gonna buy my daddy a truck and I'm gonna take his old one."
Here's a link to the entire testimony:
http://www.callahan.8k.com/wm3/jessiemsr.html
I remember hearing that there were other witnesses who discussed the reward money, but I can't recall offhand who they were. However, I know that Jessie and his father believed that Jessie would get the reward money if Jessie helped the police arrest Damien.