SAUGUS – Hockey jerseys, autographed baseballs, signed football helmets: they?re all par for the course at Sportsworld in Saugus. But this week, a purported jailhouse letter from former New England Patriots tight end Aaron Hernandez netted the memorabilia shop a whopping $18,000.Brendan Brennan of Sportsworld said Friday that a man named Karl from New Bedford began writing to Hernandez, who is in jail facing a murder charge in the death of semi-pro football player Odin Lloyd. After the two exchanged a few letters and phone calls, Brennan said the man contacted Sportsworld looking to sell one of the letters.We were here, someone contacted us and asked us if we were interested in purchasing it,” said Brennan. “We asked him to bring it up to verify it. We?ve done a lot of signings with Aaron, and we were easily able to identify that it was his signature and the outside of the envelope matched up correctly with the jailhouse.”After negotiating with the man, Sportsworld then turned around and sold the letter to celebrity gossip website TMZ.?It turns out (Karl) wrote him randomly, and I guess Aaron kind of liked the letter that he wrote him,” said Brennan. “He basically said he believed in him that he?s not guilty and hopefully he gets his day in court. From what he told me, Aaron kind of took a liking to him and I guess Aaron calls him as well and has written him a couple of letters.”In the letter, Hernandez professes his innocence and laments the “false accusations.”?The world just makes things out of false accusations and it will all die down especially when they say NOT GUILTY and all the people who turned on me will feel like crap,” Hernandez allegedly says in the letter.?God put me in this situation for a reason,” he adds later.Hernandez ends the letter by saying, “Can?t wait to sign this again when I?m playing again an [sic] prove all the haters WRONG.” He also requests the person “Keep this off social media PLEASE!”With Hernandez facing a murder charge and, according to The Boston Globe, being investigated in connection with a double-murder in Boston from last year, Brennan said he did have reservations about selling the letter.?Of course. Anybody who has a conscience does,” said Brennan. “But at the same time it?s something the public probably wants to hear from his side. It?s one of those things you?re damned if you do and you?re damned if you don?t.”While Sportsworld specializes in sports memorabilia, Brennan said they?re no stranger to more macabre items.?Someone came in with Albert DeSalvo letters and Whitey Bulger letters,” he said. “It?s weird stuff because you don?t really know what the price is to put on it ? The Hernandez thing is so big right now and everyone wants to hear his side of the story, at least this letter sheds a little light on it. It?s not an interview, but it?s the closest thing you?re going to get right now.”Karl, the purported correspondent with Hernandez, declined to comment when reached by phone Friday.