By the time the late-night argument ended, Jacqi Galles had been hoisted off the ground in a tight stranglehold and choked so vigorously that she says she nearly passed out. She fled her home and called the police on her then-boyfriend, who was charged with a misdemeanor and spared a prison sentence after pleading guilty. Moved by that case and others like it, South Dakota this year joined a growing list of states that have made non-fatal choking a felony crime, which is more serious and carries a stiffer penalty. Anti-domestic violence groups leading the effort say the laws are intended to not only secure tougher punishments for domestic abusers but also to promote awareness of a crime they say often precedes homicide - yet is chronically under-prosecuted. "For decades, we've simply lumped it into assault or battery or causing injury to another," said Scott Burns, executive director of the National District Attorneys Association. But there's a heightened awareness that this is something different. This is far more serious. Attempted strangulation cases have long vexed police and prosecutors seeking stiff penalties for attacks. The act can leave victims close to death, but unlike blows that produce a black eye or broken nose, it generally leaves few, if any, external signs of injury needed to prove a felony assault charge. An attempted murder charge is also hard to sustain in cases where suspects intend to frighten rather than kill. As a result, advocates say, suffocation cases have historically been handled as misdemeanors that don't reflect the act's severity or carry meaningful punishment. About 30 states have passed laws, most in the past decade, making it a felony under certain conditions to knowingly impede someone's breathing. Iowa, South Dakota, California and Tennessee are among recent states to act, and Virginia's governor signed a law last week. A New York law that took effect in 2010 added three classifications, from a misdemeanor requiring no proof of injury to a Class "C" felony, and yielded more than 11,000 charges in its first 14 months, according to the office on Domestic Violence Prevention. The laws, part of a multi-pronged effort to draw attention to strangulation attempts, come as advocates train police on identifying the more nuanced signs - including a raspy voice, bloodshot eyes and involuntary urination. Leading the campaign is the National Family Justice Center Alliance, a San Diego anti-domestic violence group that's received a $400,000 U.S. Justice Department grant to fund a strangulation training institute. The group's executive director, Gael Strack, has traveled the country helping lawmakers draft bills, identifying witnesses for hearings and leading seminars for police. A former prosecutor, she said she was inspired by the mid-1990s murders of two teenage domestic violence victims, including one who was strangled and whose body was set ablaze. "We all go, 'Oh my gosh, she's in danger,' but when a victim is strangled and survives, no one seeks the blood or the bruising or the swelling," she said. It's hard for them to understand that she's just like the victim who was stabbed or shot and survived. Still, bills have stalled in some states as opponents, including defense lawyers, say that enough laws are in place to protect victims and that new measures will create excessive prosecution.