"The Encyclopedia of Western Lawmen and Outlaws" by Jay Robert Nash gives a short biography on page 85.
"On July 15, 1848 Copeland shot and killed James Harvey in revenge for the murder on Gale H. Wages. Gale's father paid Copeland $1000 to carry out the murder.....He [Copeland] was hanged on October 30, 1857."
It further states that Copeland was born in 1815, that he performed various "services" for the Wages family, and the hanging occured apparently in Augusta MS.