Gallo claimed he was too drunk to know what he was doing when he finally got behind the wheel of his parents' minivan. But he should have known better.
That made all the difference for jurors, who took little more than a day to find Gallo guilty of three counts of second-degree murder rather than manslaughter.
It was the 11th time in two years that a defendant was convicted of murder in the county for killing someone while driving drunk. The verdict Monday against Gallo cemented the conservative county's reputation as a leader in the nationwide trend of prosecuting drunken drivers for murder.
The legal strategy is gaining momentum in states from New York to Alaska, as juries become less forgiving of the crime. The difference between murder and manslaughter can add years to a defendant's potential sentence.
Laws vary from state to state, but there appears to be a trend among prosecutors to charge drunken drivers with murder if they have more than one previous DUI conviction and kill multiple people, said Laura Dean-Mooney, national president of Mothers Against Drunk Driving.
In New York, a man was convicted of murder in a DUI collision that decapitated a 7-year-old flower girl on her way home in a limo from a wedding. In Missouri, a man with three prior DUI convictions was found guilty of second-degree murder for killing a 19-year-old in a drunken driving crash.
And in Alaska, prosecutors are seeking a retrial on a murder charge for a man accused of driving drunk and killing a man on his way home from a fishing trip. The first trial resulted in a hung jury.
MADD, which tracks the issue, doesn't keep statistics on the number of murder convictions for DUI-related deaths. The patchwork of local jurisdictions and differences in state laws make such numbers hard to compile.
In 2008, Orange County became one of the first jurisdictions in California to set up a special unit dedicated to prosecuting vehicular homicides - 99 percent of which are DUI-related.
Along with Gallo, those convicted included a Marine from Camp Pendleton who had no prior DUI convictions. Eight of the county's convictions are expected to reach the state appeals court.
DUI murder prosecutions in California are based on a 1981 state Supreme Court ruling that allowed fatal drunken driving crashes to be charged as second-degree murders. The state's high court ruled that DUI meets the malice standard required for murder because it shows a conscious disregard for human life.
Orange County's aggressive pursuit of such convictions began in earnest in 2004, when courts were required to advise drivers who pleaded guilty to DUI that they could be charged with murder if they committed the offense again and killed someone. Such notice is known as a Watson advisement.
In Gallo's case, prosecutors charged him with murder because he had the prior DUI conviction, had taken alcohol awareness classes and was driving on a suspended license.
He had also signed the Watson advisement when he pleaded guilty in his prior DUI case. The form was key evidence for the prosecution. He faces anywhere from 50 years to life in prison when sentenced later this year.
The tactic has come under fire from defense attorneys who say fatal DUI cases don't meet the threshold required for a murder charge.
"Some very ambitious prosecutors think they can fly a murder case by calling it malice and it got to be a fad," said Lawrence Taylor, who wrote a book about defending DUI cases. "I don't think there is any sense or logic or honesty or justice in that."
Using the Watson advisement as evidence of prior knowledge is tantamount to entrapment for defendants who might sign the paperwork years before they kill anyone in a drunk driving crash, Taylor said.
"When was it possible in criminal law or justice or anything else for a person to contractually agree or sign a statement that resulted in murder charges?" he asked. "You can't sign away your life."
Her office recently won a second-degree murder conviction against a Marine who got drunk at Camp Pendleton then rear-ended another car, killing the chief of radiology at a hospital and severely injuring his wife.
Other soldiers had taken away the Marine's keys and begged him not to drive, but he used his rank to order a lower-ranking officer to return the keys.
The district attorney's office argued that although the Marine had no prior DUI conviction, he had full knowledge of the dangers of drunken driving because others tried to stop him.
"These kinds of deaths are just has hard for victims of DUI crime to take as the traditional murders that people are more familiar with," Price said. The people who lose family members as the result of a drunk driver don't know the difference."