Oakland’s Josiah Zayner publishes a DIY gene-editing guide and once injected his own arm with DNA, while sipping Scotch, in a live-streamed event watched by nearly 150,000 people.

Does that make him a criminal?

The state is investigating Zayner, a popular biohacker and provocateur, for practicing medicine without a license, according to a stern letter issued this month by the California Department of Consumer Affairs.

It is the first regulatory challenge of the one-time NASA scientist who has earned celebrity by pushing the boundaries of do-it-yourself genetic experimentation.

Zayner, whose company sells CRISPR gene-editing kits to the public and is advised by prominent Harvard geneticist George Church, is stunned by the news and says he’ll fight the allegation.

“I am frustrated to be the target of this investigation,” he said. “I have always tried to work within the confines of U.S. laws and regulations, because I really do want to help people and not create pretend science or medicine.”

The state says somebody filed a complaint against Zayner, but a Consumer Affairs spokesperson would not discuss specifics or say who filed it. State investigators have requested an interview with Zayner, inviting him to bring an attorney.

Under California law, it is a crime “to practice, attempt to practice, or advertise practicing any treatment of the sick including diagnosis, operation, or prescription for an ailment, blemish, deformity, disease, disfigurement, disorder, injury, or any other physical or mental condition without a valid certificate or authorization for doing so.”

Violations are punishable by a fine of up to $10,000 and possible imprisonment in a county jail up to one year.

With a shock of dyed blonde hair and ear piercings, Zayner takes his inspiration from the early days of personal computing, when the Homebrew Computer Club and other hobbyists shared now-legendary ideas and experiments.

The University of Chicago-educated molecular biophysicist worked for Mountain View’s NASA Ames Space Synthetic Biology program for two years, where he engineered bacteria that could help transform Mars into a planet suitable for human life.

Since 2016, he’s focused on his company, The Odin. He says his goal is to promote do-it-yourself biology in high school classrooms around the globe.

The company’s business and science advisor is Church, professor of genetics at Harvard Medical School and director of PersonalGenomes.org, which provides open-access information on human genomic, environmental and trait data.

Critics say the company’s work raises the specter — deeply troubling to some experts — of a day when dangerous gene editing is conducted far from the eyes of government regulators, posing risk to the environment or human health.

His online company was the first to market a simplified version of the CRISPR tool to the masses — a project that, for now, is more provocative than perilous. The kit has limited applications. Most scientists would agree that his altered bacteria and yeast are quite harmless, leading brief and fairly dull lives. They can’t do much except change color, fragrance or live in inhospitable places.

His $299 frog-editing kit injects a gene-editing liquid into a tree frog’s back, causing the amphibian to double in size in four to five weeks. It doesn’t alter future generations; when the frog dies, so does the experiment.

At an October 2017 conference called SynBioBeta, a synthetic biology industry meeting held in San Francisco, he filled a syringe with gene-editing DNA and injected it into his left arm.

To a round of applause, then shared on YouTube, Zayner said, “This will modify my muscle genes to give me bigger muscles.”

Hank Greely, director of the Center for Law and the Biosciences at Stanford Law School, has watched Zayner’s work with interest.

“I suppose you might be able to make a case against a person for unauthorized practice of medicine on himself but a) depends on the statute’s wording (which I don’t know) and b) why bother?” he wrote.

“It wouldn’t shock me if Josiah had recommended some things to people in ways that could be construed as giving them medical advice, though I suspect he was careful in his wording,” according to Greely.

Zayner asserts, “I have never given anyone anything to inject or use, never sold any material meant to treat a disease and never claim to provide treatments or cures — because I knew this day would come.”

Angrily, he tweeted: “The (expletive) up part is that so many people are dying not because of me but because the FDA and government refuses to allow people access to cutting edge treatments or in some cases even basic health care. Yet I am the one threatened with jail.”