Two men charged with ambushing a suburban Pittsburgh cookout and killing five adults and an unborn child face a hearing to determine whether they'll stand trial.

Twenty-nine-year-old Cheron Shelton and 27-year-old Robert Thomas face six counts of criminal homicide and other charges in the March 9 shooting in Wilkinsburg.

Allegheny County prosecutors say Thomas fired a handgun so the guests would run for cover toward a home, where they were gunned down on a porch by Shelton, who fired an assault rifle from close range.

Authorities believe they were trying to kill a cookout guest who the suspects believe killed Shelton's friend in 2013. Nobody has been charged in that killing, and the suspected target of the ambush shooting was wounded but survived.

Defense attorneys say the suspects are innocent.