"It should be available to those whose suffering would be eased by the use of marijuana," said Robert Morgenthau. "There is absolutely no reason for not using marijuana for medical purposes. It's another weapon in the arsenal."
Morgenthau said he supports a marijuana legalization bill in the state Legislature. He said he came to support medicinal marijuana after doing research and talking to his daughter, a physician who specializes in treating drug abusers.
Williams, diagnosed with multiple sclerosis in 1999, choked back tears as he said he uses marijuana on his doctor's recommendation to relieve pain in his legs and feet caused by the neurological disease.
"There are days I don't feel like getting out of bed," he said.
Williams said he had tried other prescription painkillers but they did not control his tremors and spasms and caused side effects.
The Emmy award-winning talk show host said marijuana does not incapacitate him and he is almost immune to its euphoric effects.
Several states allow sick patients to smoke marijuana, including Alaska, California, Colorado, Hawaii, Maine, Nevada, Oregon, Vermont and Washington.
The bill legalizing medical marijuana use notes that other illegal substances, like morphine and steroids, are also permitted for medical usage.
"The law should not stand between (patients) and life and health-sustaining treatment under a practitioner's supervision," the bill text reads.