Roughly two to two and a half centuries before Jesus, the Sanhedrin, decided to annul the death penalty, until such time, as the political climate had cooled down.
So Jesus was born and raised at a time when capital punishment was suspended.
Not being Christian, seem to remember hearing it said, that Jesus taught that one could either follow Him or Mosaic Law but not both. Given that did Jesus ever call for the death penalty. If not, then it was left for those who followed Mosaic Law, not Him.