Sgt. Grant Snyder scrolled through Internet ads and Facebook pages in late July 2012, searching for any sign of recent activity by 17-year-old runaway Bobbi Larson and her friend.

The digital age has made it easier for sex traffickers to hide their business, but it also has handed police new tools. Snyder tried a range of digital techniques.

He tapped away at the laptop on his desk in the Crimes Against Children Unit of the Minneapolis Police Department, searching for leads. Sometimes he sat in his unmarked car between calls on other cases, using a tracking app on his iPhone to hunt for cellphones of suspected victims and traffickers.

In Bobbi's case, the big break came the morning of July 28, when a number associated with Bobbi's friend was discovered in a Backpage.com ad. He tracked the cellphone to a house on Oliver Avenue in north Minneapolis.

As Snyder pulled up and recognized Meranda Warborg in the back yard, he felt even more certain that the girls he had been looking for were sex-trafficking victims. Warborg had been connected to, but was not charged, in one of his previous cases.

"We're looking for two girls," Snyder remembers telling Warborg as he approached her.

She nodded toward the back door. "Inside," she said.

There he found the girls in a back bedroom of the house. Beneath a veneer of makeup and lingerie, Snyder said, they looked gaunt, dazed and tired.

As he walked them out of the house and into squad cars, Snyder was already planning how he could chip away at the defensiveness they had developed to survive on the streets.

A story spills out

Snyder led Bobbi through Minneapolis City Hall, a granite marvel of castle-like architecture, and into the first floor police station.

He found an interview room where he could sequester her from distractions -- a windowless cubbyhole the size of a large closet. He asked her to sit down at a small round table and prepared to disarm her with an approach honed over years of interviews with girls caught in similar circumstances.

She wasn't going to get in trouble, Snyder told her calmly. He was concerned about her. She didn't have to live that life if she didn't want to. Could he help her get away from it?

Bobbi was in rough shape, descending from her meth high. She kept putting her head down on the table, Snyder recalled, and couldn't stop the tears from flowing.

"My parents told me all I hang around are bad influences on me, and now that's what I turned out to be," she sobbed on a digital recording of the conversation.

"You know, I've dealt with a lot of young ladies…. I'm gonna tell ya: People don't walk down this road for no reason," Snyder told her. "You don't just walk into the life and say 'You know what? I want to be treated like shit, I want people to abuse me.' You don't walk into that."

Bobbi told him the story of what had happened after she persuaded a friend to run from their treatment program in Eau Claire. How she ended up turning tricks and giving money to a man she thought loved her. How she ended up at the house in north Minneapolis.

It was clear to Snyder that Bobbi felt ashamed as she fought back her tears. She knew she was doing illegal things, she said. She understood that cops might not look kindly upon her.

"I'm not doing anything right in this situation," she said.

Again and again, Snyder interrupted their conversation to remind her that she was a victim.

"Any guy that allows a young lady like yourself to be victimized like that … that speaks of their character. You understand that, right?" he told her. "The guys that paid you, they're rapists. They're not your friends. They're not your customers. They're rapists. You're a 17- year-old girl. K? That's unconscionable."

Bobbi isn't sure even now why her story came tumbling out to Snyder that day. Maybe it was because he didn't look like a cop. Maybe it was because he spoke with concern in his voice, not authority. For some reason, she liked him and she felt he was looking out for her.

Most of the hundreds of girls he had interviewed over the years had been battered or abused at some point in their lives -- hurt so badly that they felt worthless and were vulnerable to the sex trade. He started by assuming that was true for Bobbi, too.

"What I want you to understand is that all this stuff isn't your fault, K? … This is why a guy shouldn't hire women for prostitution, because you come from an abusive background, don't ya?" he asked.

Bobbi paused. "I've never gotten abused by family," she offered.

"Doesn't matter," Snyder said. "Were you abused by anyone?

Bobbi stammered. She wouldn't go there.

"I mean, I don't know," she said. "Not really. I mean I've been in serious situations, but never really like, I don't know."

Bobbi quickly cut off Snyder's line of questioning by saying she had to use the bathroom.

It had taken years before she admitted to her parents during treatment that before it all started, when she was just 14, two older boys had assaulted her. But she didn't tell Snyder about it that day.

After the initial interview, Snyder didn't know what to do with Bobbi. She was a sex-trafficking victim, so he didn't want to punish her by putting her in a detention facility. But he also knew she was a runaway risk. Only two beds were dedicated for juveniles rescued from sex trafficking throughout the state -- hosted by the nonprofit group Breaking Free in St. Paul.

Breaking Free differs from traditional shelters and chemical dependency programs because it focuses directly on sex-trafficking victims. Some women who walk in the door are addicted to the fast lifestyle, drugs and quick money that selling sex brings. Most have experienced trauma or violence along the way, but have trouble seeing themselves as exploited by pimps acting like boyfriends. Breaking Free helps them out of that lifestyle and offers group therapy with others who have had similar experiences.

Bobbi might want what Breaking Free offered someday, Snyder knew. But it was not a locked facility and with Bobbi's history of running away, it was too early to take her there. He consulted an attorney in the county's child protection office, then decided to take Bobbi a few blocks away to detox at Hennepin County Medical Center that night, where she could get a medical check. Later, authorities moved her to a cell at the juvenile detention center next door, a place where she could be kept safe.

When Snyder sat down with Bobbi a few days later to interview her again, he saw something hopeful: "She sounded like a kid that had a new chance."

Bobbi told Snyder she wouldn't run away again. But Snyder had worked with a lot of troubled kids over the years, and he knew it probably wouldn't be that simple. Not with her drug addiction, her capacity to slip out of treatment programs, the way she taxed the patience of adults who tried to help her.

Snyder looked Bobbi in the eye and guaranteed that if she ran again, he would find her.

Back to the streets

At the end of July, Snyder took Bobbi on a two-hour drive to the PORT Group Home in Brainerd, where girls are placed in a building with a spacious back yard and views of the Mississippi River.

It's a structured environment offering such things as behavior modification, respite care and counseling. Although it's not a locked facility, Snyder and her parents, Scott and Deanna Larson, thought she would be safe there for the time being.

Her stay didn't last long. She left almost immediately. Although Bobbi had fled "E" in Minneapolis, she was still pining for this man who had said he cared about her. She called him to come and get her, telling him to phone the group home posing as her father.

When he called, group home workers recognized it wasn't her father's voice and called Deanna. She notified Snyder.

Authorities intercepted E on his way north, before he could get to Bobbi. But by the time they made it to Brainerd, Bobbi had walked out the door and onto the streets on her own, looking for a fix.

Meth gives users a quick surge of euphoria that can last for hours, making it one of the most highly addictive amphetamines, said David Ferguson, professor of medicinal chemistry at the University of Minnesota. It alters brain chemistry so that users begin to feel good about bad situations. But it takes higher and higher doses to get to that same high again.

Bobbi met a woman who was being temporarily housed at a local hotel and stayed with her for a few days, then later in an apartment. They smoked meth together. After about a week, Bobbi called another man she had met in the Twin Cities to come and get her.

She ended up working for him, too, until he gave her a bloody lip and she left.

Once again, Bobbi was drifting from one man to another, alone this time, desperate for drugs and vulnerable to feigned affection.

A downward spiral

Bobbi stood at a bus stop in mid-August 2012 with some newfound male friends in North Minneapolis.

A black Jeep pulled up, and once again Bobbi climbed into a stranger's car. The driver introduced himself as "Trap." A tall, thin man in the passenger's seat was called "Red." Bobbi would later describe what happened next:

The three arrived at a house on 22nd Ave. N., decorated in cheer and innocence. Aqua gingerbread trim framed the windows. Children's toys were strewn in the yard. A little white picket fence sectioned off some scrubby brush.

It was Red's mother's house, they told Bobbi, but she was out of town. Much of what happened over her two or three days there is a blur, Bobbi admits.

The same progression of drugs, Backpage.com and sex trafficking began to play out in the little house. But Red and Trap were demanding and physically violent, Bobbi told police. They assaulted her, forcing her to do things that made her throw up. She would one day tell police that after that particularly brutal session with the two men, she kicked them off of her and ran to the bathroom. She turned on the shower and dropped to her knees, lingering under the stream of water.

"Well, she can take it. We've just gotta work on it a little bit," she recalled hearing one of the men say to the other later that night.

Just two blocks away, parents pushed toddlers on swings at a playground and children painted pictures and played games at a Boys & Girls Club, oblivious to what was happening to Bobbi nearby. She said about 10 men arrived at the little house and took turns with her. The money would go to Red and Trap.

"I just kind of gave up," Bobbi recalled.

Planning to try to leave the house, she started packing up her things when Trap and Red confronted her, she told police.

She recounted their heated, dangerous exchange in her police interview:

"What do you think you're doing? You still gotta make money," Red and Trap said while pushing her to the bed.

"Man, get the [expletive] out of my face," she yelled back.

"What's with the attitude? No bitch is supposed to have an attitude towards us."

"What do you expect, me getting pushed around … being with old, old men and getting money for it and then having to give it all to you guys. What do you expect, me to not have an attitude or whatever?"

Trap left the room and came back with a handgun and pointed it at her, she told police:

"Whoa, what the [expletive] do you think you're doing?" she asked, calming her voice. "I'll give you no attitude, but I don't understand why you just had to pull a gun on me."

Red grabbed a gun from his waistband.

"You better be making $500 in the next couple hours," he told her, adding "This is bullshit. I don't understand why you're packing."

With the men still in the room, she used Red's phone to text a previous trick an urgent message: This is an emergency. You need to come pick me up NOW.

A man came to get her and took her to a hotel in Brooklyn Center.

Bobbi didn't try to go home to her parents, knowing they would be upset that she had run away and would put her right back in treatment. She couldn't stand the thought of going back there, even though she understood they were doing what they thought was best.

She started surviving the only way she knew, by posting an ad on Backpage.com.

Arresting the pimps

In mid-August, inside Grant Snyder's suburban home, his wife was sitting in the living room scrolling through ads on Backpage.com on her laptop, engrossed by the case her husband was working on. She spotted Bobbi's advertisement.

Snyder called the number and did his best to imitate a Texas accent, hoping Bobbi wouldn't recognize his voice. She didn't, and invited the man she thought was in town on business to the hotel.

Police showed up instead.

Eventually, they arrested Trap, 33, whose real name is Robert Virgil Love, and Red, 30, whose name is Jeffrey John Latawiec.

Latawiec told police that Bobbi belonged to Love because Love had picked her up in the Jeep on the corner in north Minneapolis. He said Love would "go first" in having sex with Bobbi because she was his girl. Latawiec acknowledged in the police interview that he got paid after Bobbi turned tricks. "Of course," he told police. "I mean, you ain't gonna be in my house doing that shit" without paying for it, he said.

In a telephone interview from the state prison in St. Cloud, Latawiec said he and Love never acted as pimps. Sex with Bobbi was consensual, he said, and they never pulled guns on her. Latawiec said he didn't use drugs with her. He said only one or two patrons came to the house, she was there only about a day and when he learned Bobbi was turning tricks he demanded she leave. She paid him what she thought she owed him for food and shelter, he said. Love and Warborg declined to take calls to the Hennepin County workhouse seeking comment for this story.

The cases of Robinson, Warborg, Latawiec and Love began to weave through the Hennepin County court system, a long process that would unfold from the summer of 2012 through autumn of 2013.

In recent years, the approach of prosecutors toward traffickers has intensified, said Hennepin County Attorney Mike Freeman. "I think we're more aggressive in the charging. I think we're a little bit more aggressive in what we're asking for in terms of sentences," he said. "I think we're more aware of how exploitive this is."

As the legal process wore on, Snyder and others did their best to wrest Bobbi from the grip of addiction and life on the streets.

All the while, the powerful coalition that had formed in Minnesota to fight sex trafficking was working to make sure this damaging, dirty world was brought sharply into public consciousness.

Ramsey County Attorney John Choi grew more creative in his efforts to overhaul prosecution of pimps and treatment of girls who were trafficked, including a proposal to file civil no-contact orders against alleged perpetrators when authorities needed more time to build cases.

Groups around the state that had been working against child sex trafficking began to close ranks.

Sisters in the Order of St. Francis in Rochester, wielding PowerPoint presentations, held seminars featuring a former trafficking victim. They drew crowds at local libraries and community colleges, where they aimed to make people aware that sex trafficking was going on locally and raise money to get the word out.

The Minnesota Trucking Association had signed on to the national "Truckers Against Trafficking" campaign, and drivers were being taught how to spot and help the women they once called "lot lizards" -- those who roamed truck stops along the interstate highway corridors, knocking on the doors of big-rig cabs offering sex for money.

Momentum for change in Minnesota was building.

Decked out in a black suit coat and tie, Snyder addressed advocates fighting trafficking last May in a meeting room at the Crowne Plaza hotel in downtown St. Paul.

He told the harrowing story of an underage sex-trafficking victim from northern Minnesota identified as "Bobbi."

"What Bobbi's story illustrates is the incredible depth of our failings as law enforcement," Snyder said. "Bobbi was a kid that had all of the vulnerabilities up front."

After police pulled Bobbi from the streets of Minneapolis, he explained, "we got her into what at that time appeared to be our best alternative, and that was a treatment program up in northern Minnesota. That didn't work for Bobbi and she escaped from there and eventually ended up back on the streets where we had to rescue her again. This is the backdrop against which we've had to learn to do our job better."

More than 700 advocates showed up during the weekend conference put on by Breaking Free. They were trying to convince the Minnesota Legislature to put more money toward combatting sex trafficking and helping victims. Later that month they succeeded, when lawmakers agreed to spend $2.8 million -- the largest state investment in the country.

The money will add 12 to 14 beds for sex-trafficked children in safe facilities with counselors who understand their special trauma.

The Legislature also changed state law so that any prostituted person under the age of 18 would be treated as a victim. U.S. Sen. Amy Klobuchar, D-Minn., recently announced plans to introduce legislation to take Minnesota's "Safe Harbor Law" model national. U.S. Rep. Erik Paulsen, R-Minn., introduced a bill in July intended to prevent runaways from being pulled into the sex trade and help those caught in it to escape for good.

Police and prosecutors already had treated Bobbi as a victim while building cases against the four people accused of being her pimps.

A glimpse of hope

Bobbi kept talking to Snyder on the phone as prosecutors put the cases together.

They spoke to each other as if they were family. Instead of answering her calls with a typical "hello," Snyder would immediately show concern: "Hey, you OK?"

Bobbi grew anxious when she thought she might have to face the defendants in court and tell the world what she had been through. She continued treatment for drug addiction as well as mental health counseling. The trauma, guilt and shame weighed heavily on her mind, making the temptation to get high even stronger.

The Larsons and administrators at Two Harbors High School worked to design an academic program that would allow her to take classes along with her counseling so she could graduate with her class. She hoped to go to cosmetology school. Then, maybe someday, she said, she could work with police on sex-trafficking cases.

The possibility of a brighter future lay ahead. Graduation day was fast approaching. But Bobbi's family wondered if she could make it over the long haul. Now that she was 18 and an adult, mistakes with the law would go on her record. The stakes would be higher.

Could Bobbi Larson save herself?

Read Part 4: Struggling to find a way forward

Go to Part 1: A teen's sex trafficking ordeal

Go to Part 2: Lured by drugs, used by pimps