Prison authorities called off the execution after failing to find a doctor, nurse, or other person licensed to inject medications to give a fatal dose of barbiturate, said Vernell Crittendon, a spokesman for San Quentin State Prison.
"We are unable to have a licensed medical professional come forward to inject the medication intravenously, causing the life to end," he said.
CBS News legal analyst Andrew Cohen reports stopping an execution at the last minute isn't unusual, but it almost never happens for a medical reason. In this case, with the trial judge already on record as saying he believes Morales ought to get a life sentence instead of capital punishment, the complications going forward are intense, Cohen says.
"This is now a big issue in capital cases - the way the punishment actually is administered," says Cohen. "Just about a month ago, in fact, the U.S. Supreme Court agreed to hear a case about how lethal drugs are administered and whether they violate the cruel and unusual punishment clause of the 8th amendment."
"This case is going to put more pressure on judges and legislators to try to answer more effectively the questions that doctors or, in this case anesthesiologists have, about the lethal drugs that are used in executions and the impact they have on capital defendants while they are being executed," says Cohen. "It's fairly clear that the old way of doing things is going to have to change."
It is not clear when the execution will be carried out, but the delay could last for months because of legal questions surrounding California's method of lethal injection.
The 24-hour death warrant for Michael Morales was set to expire at 11:59 p.m. Tuesday. After that, state officials have to go back to the trial judge who imposed the death sentence in 1983 for another warrant.
Hearing the news of the execution's postponement - for the second time in a single day - Barbara Christian, whose 17-year-old daughter Terri Winchell was killed by Morales - called the judicial system "ridiculous" and indicated that she is angry and disappointed.
"I'm totally disillusioned with the justice system," said Christian. "We've been waiting 25 years with the expectancy that he is gonna pay for his crimes... It feels like we just got punched in the stomach."