Like 44 million other Americans, Kevin Robertson popped an Ambien recently to help him sleep. Next thing he knew, he woke up in jail -- facing criminal charges from a non-injury crash in Santa Clara, including driving under the influence of a drug and resisting arrest.

Employing a legal strategy cropping up in courtrooms around the country, attorney Jennifer Redding argued he was "sleep-driving,'' a rare but recognized side effect of Ambien -- and the jury found him not guilty. But because Robertson is on parole for bank robbery, he is set to be tried again Wednesday in San Jose for the same offense by a parole-board commissioner, who could decide the incident was a violation and sentence him to up to 180 days in jail.

The case puts the Bay Area spotlight on the controversial "Ambien defense,'' a strategy that's been tried in courts from Massachusetts to Texas to Orange County with mixed results. Outright acquittals like Robertson's are rare, but the argument has lead to plea bargains and lighter sentences -- as well to disbelief and convictions.

"The Ambien defense is happening all over the place,'' said Richard Uslan, a New Jersey attorney credited with winning a 2006 case, one of the first in the nation. "There is skepticism but that hasn't stopped attorneys from advancing it.''

The sleep-driving phenomenon surfaced in the mid-2000s after several crashes, including a widely publicized Ambien-related accident in 2006 involving Patrick Kennedy, the former congressman from Rhode Island and son of the late Sen. Edward Kennedy.

In 2007, the Food and Drug Administration warned that Ambien and 12 other insomnia drugs have the potential of causing rare "complex sleep-related behaviors" which may include "sleep-driving, making phone calls and preparing and eating food (while asleep)." The agency defined "sleep driving" as "driving while not fully awake after ingestion of a sedative hypnotic, with no memory of the event" and advised drug makers to place stronger labeling on their products.

National strategy

In 2009, the Ambien strategy -- also referred to as the Zombie defense -- helped get a Fresno woman who fatally struck a mother of 11 children acquitted. Two years earlier, a judge found a Massachusetts lawyer who killed a man while sleep-driving not guilty.

"It's a legitimate thing -- it really does affect people,'' said Patrick Hancock, a San Antonio, Tx. attorney and former prosecutor who represented a flight attendant using an Ambien defense this spring. "Most people think it won't happen to them, but it can.''

Many cases, including Hancock's, involve people who drank alcohol while on Ambien, even though there is an explicit label warning against it.

After drinking five or six glasses of wine and taking Ambien, Hancock's client Julie Ann Bronson sleep-drove her Mercedes convertible into a mother and two children, severely injuring an 18-month-old girl. Bronson pleaded guilty and opted to be sentenced by a jury, which is possible under Texas law. Sympathetic to the Ambien defense, the jury recommended a sentence of only 10 years probation rather than the maximum of 10 years behind bars. The judge added a six-month term in jail as a condition of probation, which she's now serving.

In the Santa Clara County case, no alcohol was found in Robertson's blood. But Robertson, 45, was in terrible health and had been prescribed a battery of seven medications by doctors at Kaiser Permanente, including Ambien, benadryl and morphine, which showed up in blood test after the June 20 crash.

Many health issues

The health issues that figured in Robertson's case began in 2010 after he served after serving about 31/2 years for four unarmed bank robberies that netted him $8,000 and were counted as strike crimes. He said his previous convictions were for felony joyriding, stealing mail and altering checks. He also used to be addicted to snorting heroin, but said he has been clean since 2006.

Diagnosed with Hepatitis C, he underwent an eight-month treatment with interferon to prevent the virus from scarring his liver and leading to cirrhosis, liver failure and liver cancer. Many liken the treatment to chemotherapy; in Robertson's case, it caused severe side effects like projectile vomiting, itching and insomnia.

Then he developed a staph infection, which began eating into his spine, requiring extensive back surgery and several stays in the Intensive Care Unit. He remains in chronic pain with abnormal liver functions and had been treated at a Kaiser emergency room the morning of the crash.

After leaving the hospital, he said he returned home to his sister's Willow Glen house, ate dinner, took an Ambien and laid down at 8 p.m. with his black lab Lily.

"Then it was 1:30 a.m. and I woke up shackled to a chair,'' he said. "I had no idea of what had happened. I've been guilty all my life of every crime I've been committed of, but not this.''

Deputy District Attorney Cameron Day disagrees. He argued that Robertson had "special notice'' of Ambien's risky side effects because of a previous crash about seven months earlier in Lake Tahoe. Robertson had taken an Ambien on his way home. Classified as a quick-acting drug, it kicked in before he got there and he crashed into a pole on the side of the road. Officers found him asleep in his truck and arrested him on suspicion of driving under the influence of a drug.

"One of the things we were trying to prove was he should have known the effect of Ambien in general and on him in particular after that,'' said Supervising District Attorney James Gibbons-Shapiro.

Still in jail

However, charges were never filed and the incident did not count as a parole violation. Robertson testified he never took the drug again unless he was home and ready to immediately go to sleep.

The jury believed him and after a four-day trial took less than an hour to render a not-guilty verdict, on July 30. Robertson has been in jail since the incident, awaiting his parole revocation hearing.

The parole commissioner is not required to follow the jury's example. Unlike in a trial, where prosecutors must prove the charges "beyond a reasonable doubt,'' the commissioner weighs the evidence under a lesser standard -- "preponderance of the evidence.'' The standard is lower because parole is an extension of incarceration, not equivalent to freedom with its attendant rights. Prosecutors do not participate in the hearing.

To house a minimum-security inmate like Robertson at Elmwood jail, it costs about $116 a day. But in Robertson's case, it's been far more expensive because he's been rushed at county expense to the hospital four times.

"It's a waste of taxpayers money to keep him locked up for something for which he was not guilty,'' his attorney, Redding, said. "Twelve members of the community were convinced he was not conscious when he drove the car and resisted arrest. He was essentially like a chicken with its head cut off.''

Regardless of what happens at the hearing, Robertson is certain of one thing -- he'll never take Ambien again.

Contact Tracey Kaplan at 408-278-3482