NEW : Troy Davis 's sister says she is disappointed and will keep fighting . The evidence Davis presented is `` not credible '' or `` smoke and mirrors , '' court finds . Score: 6 He was convicted in 1991 but witnesses have since recanted their testimony .
NEW : Troy Davis 's sister says she is disappointed and will keep fighting . The evidence Davis presented is `` not credible '' or `` smoke and mirrors , '' court finds . Davis faces execution for killing an off-duty police officer in 1989 but says he is innocent . He was convicted in 1991 but witnesses have since recanted their testimony .