CHARLOTTE, N.C. — Malcolm Hartley pleaded not guilty Thursday morning in federal court to killing Doug and Debbie London in their Lake Wylie home last October.
Investigators believe another man, Jamell Cureton, orchestrated the murders to prevent the London's from testifying against him after police said Cureton robbed the couple's mattress store months before.
STORY: Judge to review evidence seized from accused gang member's jail cell
New documents released Wednesday revealed detailed conversations Cureton had while he was in jail and also letters he sent discussing the plan.
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Those documents reveal investigators traced phone calls Cureton made from jail to Hartley. The documents also detail a letter found inside Cureton's cell.
READ MORE: CMPD: Cureton, accused of Lake Wylie couple's murder, also suspect in 2013 killing
One letter explains a story police believe Cureton created to explain the mattress store robbery. In the letter, Cureton said he'll make up a story that Doug London owed them money for drugs.
It goes on to explain how Cureton and his accomplices will tell police when they went to the store to collect the money. Doug London handed over a bank bag and then shot Cureton to make it look like a robbery. Cureton's goal, according to his letter, was to discredit London.
One of Cureton's letter read:
"An as fore that old man goes we needa say he smoke crack and owed 1 of us some money. We needa come up with something because he showed up to every cort date."
The letter ended with, "I need you to destroy this letter."
IMAGES: Gang members charged in federal indictment
Channel 9 also learned Cureton has a new attorney.
Five other accused members are also charged with the London's murders. Investigators believe Cureton and the others involved are members of the United Blood Nation gang.
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