DENVER | The Colorado Court of Appeals has upheld the conviction of a man on death row who killed a potential witness and his fiancée.

The court ruled Thursday that Sir Mario Owens got a fair trial and there was no misconduct by prosecutors.

Owens appealed his conviction, claiming 17 witnesses on probation may have received special treatment and a judge erred by limiting access to potential witnesses out of concern for their safety.

Owens was convicted in 2008 of killing Javad Marshall-Fields, a potential witness in a murder trial, and Vivian Wolfe, Marshall-Fields’ fiancee.

Marshall-Fields and Wolfe were stopped at an intersection in the Denver suburb of Aurora when they were shot. Marshall-Fields was expected to testify against Owens in another murder case.