The state of California has indefinitely postponed the execution of convicted killer Michael Morales after his killing was put off for a second time. The case has raised concerns over the role of doctors in the death chamber and spawned a court battle over lethal injection methods. Morales was initially supposed to have been executed just after midnight Tuesday. But his execution was put off after doctors withdrew from the process, claiming their role threatened to be “medically unethical.” A second attempt to put Morales to death also passed late Tuesday when state officials could not find any medical professionals willing to take part. The doctors were originally brought in to provide Morales with anesthesia after his attorneys argued that the three-part lethal injection process violates the 8th Amendment prohibition against cruel and unusual punishment.