Supernatural's AJ Buckley has joined the TNT series Murder In The First.
Taye Diggs and Kathleen Robertson both lead the crime drama.
Murder In The First will chronicle a single murder case, exploring an investigation to arrest and the trial, Deadline reports.
Diggs and Robertson will star as two detectives, with Buckley on board playing Marty "Junior" Mulligan, Robertson's brother.
The series, which has already been picked up for a second season, comes from TV veterans Steven Bochco and Eric Lodal.
Buckley has recently been seen in FX's Justified and Longmire.
