LOS ANGELES (CBSLA.com) — California has become the largest state in America to allow terminally ill patients to legally end their lives using doctor-prescribed drugs after Gov. Jerry Brown signed the “End of Life Option Act” Monday.

In a letter addressed to the California State Assembly, the governor wrote: “In the end, I was left to reflect on what I would want in the face of my own death. I do not know what I would do if I were dying in prolonged and excruciating pain. I am certain, however, that it would be a comfort to be able to consider the options afforded by this bill. And I wouldn’t deny that right to others.”

Brown, a lifelong Catholic and former Jesuit seminarian, had refused to comment on the issue until now.

Opponents said ABX2-15 legalizes premature suicide. But supporters call that comparison inappropriate because it applies to mentally sound, terminally ill people and not those who are depressed or impaired.

Christy O’Donnell, who has stage-4 lung cancer, said she didn’t think it would have happen in her lifetime. “I was just really in awe. I kind of kept saying wow,” O’Donnell said.

Despite chemotherapy, the former Los Angeles police officer’s cancer spread and was given only a few more months to live. She hopes she survives long enough to end her own life when she chooses to do so.

“If I do live that long, yes, it will be my choice to obtain aid and dying. But if I don’t, I’ll be stuck with what all Californians have been stuck with prior, which is terminal sedation. My daughter will have to watch me deteriorate over days or weeks,” O’Donnell said.

Religious groups and advocates for people with disabilities opposed the bill and nearly identical legislation that had stalled in the Legislature weeks earlier. They said it goes against the will of God and put terminally ill patients at risk for coerced death.

Dr. Aaron Kheriaty, the Director of Medical Ethics at UC Irvine, urged the state legislature to reject the bill, saying that low-income and uninsured patients, who are suffering from serious illnesses, may feel great pressure to end their lives prematurely.

“For well enfranchised folks like Governor Brown, that might not be a real problem or real issue. But for the millions of other Californians that don’t have access to good health care, this could be one more thing that pushes them more and more to the margins,” Kheriarty said. “Those folks might feel like out of a sense of duty or obligation to others, I really ought to pick this assisted suicide option, even if it’s not something that I would otherwise be inclined to do.”

Supporters of the “End of Life Option” law said it is filled with safeguards to make sure that doesn’t happen, including the requirement for confirmation that a patient is terminal from two doctors before they can be considered a candidate for the program.

And doctors must consult with the patient in private to find out if pressure has been applied on them. The patient must be physically capable of taking the medication and submit several written requests. In the end, the patient–not the doctor–must administer the fatal dose.

The law goes into effect next year, 91-days after the legislative special session ends. The law will expire in 10-years, unless lawmakers renew it.

The “End of Life Option Act” passed on Sept. 11 after a previous version failed this year. Brittany Maynard, 29, suffering from terminal brain cancer, was the leading voice for a right-to-die law in California. She moved from the San Francisco Bay area to Oregon to end her own life in 2014 . Her widower had an emotional reaction to Gov. Brown’s announcement.

“The reason that my wife’s name became known or now that I continue this is because my wife died. She spoke up and made a difference. And so in that regard, the emotions are feeling proud of her,” said Dan Diaz, Maynard’s husband.

California’s measure came after at least two dozen states introduced aid-in-dying legislation this year, though the measures stalled elsewhere. Doctors in Oregon, Washington, Vermont and Montana already can prescribe life-ending drugs.

Maynard’s family attended the legislative debate in California throughout the year. Maynard’s mother, Debbie Ziegler, testified in committee hearings and carried a large picture of her daughter as she listened to lawmakers’ debate.

In a video recorded days before Maynard took life-ending drugs, she told California lawmakers that no one should have to leave home to legally kill themselves under the care of a doctor.

“No one should have to leave their home and community for peace of mind, to escape suffering, and to plan for a gentle death,” Maynard said in the video released by right-to-die advocates after her death.

The Catholic Church targeted Catholic lawmakers before the bill’s passage and urged the governor to veto it.

“Pope Francis invites all of us to create our good society by seeing through the eyes of those who are on the margins, those in need economically, physically, psychologically and socially,” the California Catholic Conference said in a statement after its passage. “We ask the governor to veto this bill.”

The measure was brought back as part of a special session intended to address funding shortfalls for MediCal, the state’s health insurance program for the poor.