COLUMBIA, Mo. -- A Columbia youth who was sentenced to 27 years in prison for killing a 12-year-old girl has lost an appeal of his second-degree murder conviction.

David Dewey was convicted last year of second-degree murder in the beating and strangulation of Sheena Rae McDonald. Dewey, who was 16 at the time, was tried as an adult in the slaying.

Dewey lived near the area just north of Columbia where McDonald was found dead the night of May 14, 2000. Neighbors discovered the body when the girl didn't return home from a walk.

In the appeal of his conviction, Dewey raised four objections involving the prosecutor's questioning of an expert witness and evidence that had been introduced during his trial.

In an opinion released Tuesday, the Western District Court of Appeals in Kansas City rejected all of Dewey's objections and affirmed his conviction.