Brown, 52, was shot and killed Wednesday morning at Fit Farm Fitness Club on Braemar Avenue in New Kingston.
On Thursday, Mullings wrote a heartfelt message in tribute to the late fitness instructor.
"Love is forever and will always triumph over death. It was deeper than boxing, not flesh and blood but the heart," Mullings wrote.
"I’d give anything to relive these memories again. You tried to give me the world but your greatest gift was believing in me, how will I get by without you," he added in the post which included a photo of the pair sharing a hug after one of Mullings' victories.
Police report that Brown was shot dead about 5:40am as he exited the gym. Investigators are yet to determine a motive for the killing.
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