SACRAMENTO, Sept. 25 – The death penalty will be mandatory in California for 11 categories of murder beginning Jan. 1, 1974, under a law signed Monday by Gov. Reagan.

Some legal experts, including state Atty. Gen. Evelle Younger, say four other categories already carry an automatic death sentence under guidelines prescribed by the U.S. Supreme Court.

However, California has had no death penalty law as such since the state Supreme Court declared it unconstitutional on Feb. 18, 1972, saying the penalty was “cruel or unusual punishment.”

In signing the bill, Reagan noted it was a direct result of the 67 percent support given by the state’s voters to a death penalty initiative on last November’s ballot.

“I’m sure we all regret the necessity of having to sign such a bill,” the Republican chief executive told reporters at the bill-signing ceremonies.

“But I do have the feeling of satisfaction that comes from doing something that you know is right. There is no way of knowing how many lives of innocent, law-abiding citizens this legislation will save.”

Reagan and other supporters of the new law say they believe the death penalty is a deterrent to crime.

The new law will only cover murders committed after the end of 1973 and will have no effect on the 10-year backlog of death row inmates in the state. These 105 men and five women — including Sirhan B. Sirhan, assassin of Sen. Robert Kennedy, and five members of the Charles Manson family — have received changes in sentence from death to life in prison.

More than six years have passed since the last execution in the green gas chamber at San Quentin, and there have been only two in the last decade.

The new law may face a court battle before it is used and will automatically come up for review by the state Supreme Court the first time it is.

The American Civil Liberties Union has charged that the measure is “legally defective and unconstitutional.” Other opponents argue that the law’s mandatory provisions will result in hundreds of executions every year.

But the author of the bill, state Sen. George Deukmejian, R-Long Beach, has said it does not infringe upon the constitutional rights of defendants because the governor still retains the power to commute sentences to life in prison.

At Monday’s bill-signing ceremonies, Deukmejian also pointed out that California law requires that all death sentences automatically be reviewed by the state Supreme Court, so the law will be tested the first time it is used.

Younger was also at Reagan’s side for the ceremonies, and he told reporters that critics of the measure are in the minority, considering the 2-1 favorable response to capital punishment on last year’s Prop. 17.

“We’re not as anxious to answer the critics as we are to respond to the will of the people,” he said. “We have to give the people the protection they demanded.”

The law applies the mandatory death penalty to the following crimes:
— First-degree murder of a prison guard.
— First-degree murder of an on-duty peace officer.
— Murder for hire.
— Multiple murders.
— First-degree murder by anyone with a prior first degree murder conviction.
— Murder of a witness in a criminal case,
— Train-wrecking resulting in death.
— First-degree murder in commission of robbery or burglary of an occupied residence.
— First-degree murder during a rape.
— First-degree murder in which a kidnapping is involved.
— First-degree murder during lewd conduct involving a child under 14.

The other four crimes which some legal experts say already carry the death penalty in California are treason against the state, train derailing that causes serious injury, perjury that leads to execution of an innocent person, and the murder of a guard or other nonprisoner by a life-term convict.

The U.S. Supreme Court ruled 5-4 on June 29, 1972 that “the imposition and carrying out of the death penalty constitutes cruel and unusual punishment in violation of the 8th and 14th amendments,” to the U.S. Constitution.

The court’s ruling did not ban capital punishment in all cases, but instead had the effect of setting up certain guidelines under which it would be legal.

Backers of the new state law are confident it will meet those requirements.

Also present for the bill-signing ceremonies were Santa Cruz County Sheriff Doug James, president of the state sheriff’s association, and Roscoe Antrin, president of the Correctional Officers Association.

The death penalty bill was hung up for several months in the Assembly Criminal Justice Committee, which finally voted 4-3 to substitute life in prison without possibility of parole for the mandatory death feature.

But on the Assembly floor, the pro-death penalty forces easily won enough votes to amend the bill back to its original form and pass it. The Senate overwhelmingly concurred.

By LEE MARGULIES