TRENTON -- The five accused sex traffickers from Bergen and Passaic counties advertised their victims on backpage.com, keeping them at motels across the state and forcing them to have sex with older men.

The four men from Hudson County allegedly sold off girls as young as 13, using violence and threats to control them. One girl was held at gunpoint.

And the five defendants from an international trafficking ring admitted bringing young girls from Mexico with hopes of living in America, putting them to work in brothels down the Jersey Shore.

These cases, said state Division of Criminal Justice Director Elie Honig, are the grim face of "modern slavery" in New Jersey.

Far from the stereotype of the lone pimp and willing prostitute, Honig said, these sex traffickers work in networks and practice fraud and coercion. They rely on technology to find and advertise their victims -- many of them underage and vulnerable, from New Jersey's cities and suburbs or lured from abroad.

And prosecutors, armed with stiffer state anti-trafficking laws, are putting the ones they catch away for longer, Honig said.

Law enforcement officials and victims' advocates gathered in Trenton Friday for the state's sixth annual human trafficking awareness event, which coincided with President Barack Obama's declaration of January as National Slavery and Human Trafficking Prevention Month.

There they marked the 150th anniversary of the 13th Amendment, which abolished slavery, by drawing attention to its modern forms: child soldiers, indentured laborers and those coerced into prostitution.

"When you boil it down to its basic elements, and you look through the prism of history at modern-day slavery, you see a lot of commonality," said Kenneth B. Morris, Jr., the keynote speaker and founder of Frederick Douglass Family Initiatives. Education and awareness, Morris said, was integral to preventing young people from falling victim to traffickers.

While human trafficking is an international crisis, law enforcement officials said they're making progress routing out traffickers here in New Jersey.

Three years ago, Gov. Chris Christie signed the Human Trafficking Prevention, Protection, and Treatment Act, which made it easier for prosecutors to charge those running prostitution rings with human trafficking, stiffened penalties and set up an assistance fund for survivors of sex trafficking.

The measure also created a study commission to evaluate New Jersey's approach in fighting trafficking and make recommendations to the governor and the Legislature. The commission's chairman, Atlantic County Prosecutor James P. McClain, said the panel's first annual report will be released in coming days.

"It's a very broad problem to get your mind around," McClain said.

But authorities say the law's passage is starting to bear fruit.

Last June, a New York woman became the first person to use a provision in the law that allows trafficking victims to vacate criminal charges stemming from their forced prostitution.

The woman, identified only by the initials M.S., struggled through an abusive childhood and bouts of drug addiction, losing her child and falling prey to a sex trafficker that operated a sprawling prostitution network.

Atlantic County Assistant Prosecutor Danielle S. Buckley said she had seen her share of tragedy in her years working in her office's special victims unit.

"M.S. was one of the most gut-wrenching I'd ever seen," she said. "I had to get up from my desk reading her petition."

M.S. worked with authorities and testified against her trafficker, who is now serving a 23-year federal sentence. Her prior convictions for prostitution and defiant trespass were wiped clean, making it easier for her to find work, Buckley said.

Earlier this month, Charles P. Torres, one of the first people indicted under the new human trafficking law, was given 20-year state prison sentence for recruiting a 15-year-old girl to work as a prostitute in Essex and Hudson counties.

Honig said the law makes it easier to charge those who target minors with human trafficking.

"The one thing the statute does that's important to us as prosecutors is it makes the trafficking of an underage person -- boy or girl -- automatically human trafficking," he said. "Under the old statute, you still had to show force or coercion. Our law now reflects reality."

S.P. Sullivan may be reached at ssullivan@njadvancemedia.com. Follow him on Twitter. Find NJ.com on Facebook.