His signature at least temporarily halts a hotly-contested, 10-month debate that drew emotional testimony from lawmakers and cancer patients as well as disability advocates and members of the religious community.
The long-standing issue over physician-assisted suicide in California was reignited late last year amidst widespread media coverage of Brittany Maynard, a 29-year-old terminally-ill California resident, moved to Oregon to end her life legally, allowed under that state's Death With Dignity law.
Physician-assisted suicide is notably different from euthanasia. In the former, patients with a terminal diagnosis formally request a prescription from a doctor for a fatal dose of a drug (generally in pill form) which they can administer themselves privately when they wish, according to the end-of-life resource site Comfort Care Choices.
Euthanasia, on the other hand, involves a physician or other healthcare provider deliberately administering treatment -- such as a lethal injection -- to end a patient's life, with or without the patient's consent. Although not allowed anywhere in the U.S., the practice is legal in several northern European nations, including Belgium and the Netherlands.
Supporters of physician-assisted suicide argue that these laws allow terminally ill patients to avoid unbearable suffering and die on their own terms in a humane and dignified way. It also allows greater accountability and state oversight of the process, they contend, without taking away other end-of-life care options, giving patients more autonomy to make their own end-of-life decisions.
Those against the law include the Catholic Church and a number of other religious institutions who argue that life is a gift from God and should not be prematurely shortened under any circumstance. Other opponents fear that the law could result in caregivers pressuring patients to end their lives as a way of saving money or easing the burden of care.
There is also strong concern that because physician-assisted suicide is often cheaper than end-of-life care, it may influence decisions made by patients, doctors and insurance companies. And, some opponents argue, it can be very difficult for doctors to accurately predict how much time certain patients have left live and how much influence intensive care can have in prolonging their lives.