BOSTON (CBS) – A local sports memorabilia shop has confirmed they were the ones who sold Aaron Hernandez‘s now-famous jailhouse letter to TMZ, and they received a pretty penny for it.

Phil Castinetti, the owner of Sportsworld in Saugus, told WBZ NewsRadio 1030 on Friday that he bought the letter from a fan who said he corresponded with Hernandez , who is currently being held without bail at the Bristol County Jail on charges of murder in the shooting death of Odin Lloyd.

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The fan had written to Hernandez because he said had served time in the same prison. He received a letter back from Hernandez, proclaiming his innocence, and after going back and forth, agreed to sell it to Castinetti on Wednesday.

 

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Castinetti says he paid $4,500 for the letter, which he turned around and sold it to TMZ for $18,000.

“It was kind of eerie, knowing you have a letter that Hernandez had just written,” said Castinetti. “You read all the crazy things he’s been accused of, so it’s just a little weird.”

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Before selling it though, Castinetti made sure it was real. He compared Hernandez’s signature to autographs he has in the store, and that he believes it is 100-percent authentic.

“I’ve been in the business for almost 30 years and authenticating autographs is one of the things I do the most,” said Castinetti. “It was pretty easy; he has a distinct signature and it would be impossible for someone to copy it the way it’s done. It’s pretty easy to tell.

“I’m 100-percent positive it’s real,” he said.

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While he received $18,000 for it, Castinetti isn’t sure what the letter is actually worth.

“If he is found guilty, I think it will be worth some serious money because of what is said in the letter,” he said.

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“I’ve never really handled anything like this. I’ve been doing this a long time and we’ve had some major events in sports memorabilia. This has turned into probably the biggest memorabilia event ever.”