When Idaho State Police Cpl. Kevin Kessler pulled over the speeding vehicle on Interstate 90 in the early afternoon of Dec. 13, he thought it would be a routine traffic stop like countless others he makes during his shifts working in Shoshone County.

Well, that is until he made his way up to the vehicle he'd stopped in the eastbound lane near Pinehurst.

The driver of the vehicle, an illegal immigrant named Serafin Jaimes Moreno, was acting suspicious, according to Kessler. On top of that, Kessler could tell the inside of the vehicle had been altered in a way he'd seen plenty of times before.

The experienced officer was sure from the driver's suspicious behavior Moreno wasn't just making some innocent trip across the country. Kessler suspected the man was trafficking drugs.

"We see what is normal all the time, so it's pretty obvious when it's not normal," Kessler said. "It's pretty glaring when you get someone trafficking ... I don't get any information beforehand. I don't know until I get in the traffic stop. Once you've been through training, you kind of just know."

Kessler's instincts hadn't failed him. When the officer asked the 40-year-old driver if he could search the vehicle, Moreno gave written consent. Kessler didn't realize he'd be seizing an enormous 120-pound shipment of marijuana from the suspect who has been linked to the Mexican Drug Cartel.

It was Kessler's fourth big marijuana bust since November 2011. None of the incidents are related, but from the details in each case, it's kind of hard to tell them apart.

Kessler pulled over Minnesota native Brandon Ray Barry on Nov. 14, 2011, heading eastbound on I-90 near Pinehurst after Barry's car crossed over the marked fog line and failed to use the headlights in reduced visibility. Kessler thought Barry was acting suspicious and a subsequent search found 28.5 pounds of marijuana in Barry's vehicle.

A few months later on March 29, Kessler stopped Portland, Ore., native Samuel Marso heading eastbound on I-90 for what he thought would be another routine stop until he noticed the suspicious behavior he's been trained to catch. A search of the vehicle uncovered 35 pounds of marijuana.

On Oct. 30, Kessler made another bust on Interstate 90 near Pinehurst, this time uncovering the biggest load of marijuana he'd seized until the Moreno arrest. Brian Taber of Wisconsin was pulled over for failing to observe road instructions and having illegally tinted windows. Kessler noticed large duffle bags in the vehicle and Taber acting suspiciously. After getting a K9 unit, the corporal uncovered 80 pounds of marijuana.

The cases are all similar, Kessler admits, but he said none are connected. He said the traffickers all appear to be from different organizations. And while some of those organizations are small-time, Kessler said Moreno was part of a crime group well known worldwide for their drug trafficking activities.

"Some of them are a part of some organization, and most of those are just home-grown," Kessler said. "[Moreno] was definitely cartel-related. We don't see cartel activity this far north very often, but [the arrest] proves the cartel does come through occasionally."

And while Kessler said it's just "a random coincidence" most of the stops have been around the Pinehurst exit, it's no mere coincidence all of the traffickers have been heading eastbound on I-90.

Kessler said the highway is notorious for being a major route used by drug traffickers.

"Law enforcement knows I-90 is a major route used by drug traffickers to transport large amounts of drugs and drug-related money," Kessler said. "I am just doing my part as an ISP trooper to interdict those individuals as best as I can."

Moreover, Kessler said the traffickers are always heading east because the profits for marijuana and many other drugs increases exponentially as they head east.

"[Drug dealers] can get up to double the value in the east. The further east they make it, the more money they get," Kessler said.

Moreover, the West Coast from California up through Oregon into Washington is an area well known for growing a great deal of marijuana each year. Kessler called the region a source area for marijuana across the nation.

All in all, Kessler has seized around 350 pounds of marijuana in his career, with 315 pounds of that from the four stops in Shoshone County in the last year. And that 315 pounds has a street value in the west of about $3,200 a pound, or around $1,008,000 total - a sum that would have skyrocketed if the traffickers had made it east.

With such large quantities of drugs found on these traffickers, each one convicted faces a mandatory minimum of five years in prison and no less than a $15,000 fine.

Barry received a suspended sentence after making a plea agreement, while Marso awaits sentencing for his plea agreement. Barry received a 180-day suspended sentence and a fine of $3,500, while the terms of Marso's plea calls for 60 days in jail and $5,000 in fines and court costs.

Kessler said he respects the fact that the court has a job to do, but he wishes they could send a message to people that drug trafficking is a big deal.

"I just have to remember I have my job to do and the court has its job to," Kessler said. "I wouldn't say I'm frustrated. The main job is to get the drugs of the streets, but I think it would be good if the court imposed the mandatory minimums so people will know they'll have to actually go away for a few years if they traffic drugs."

While the convicted were caught trafficking, none of the offenders or alleged offenders were carrying any weapons, and they've cooperated with police. Kessler said he's been lucky none of the people he's pulled over has been violent in what could have become an ugly situation.

"A law enforcement traffic stop is always a dangerous thing because you never know," Kessler said. "Luckily, I haven't had anyone try to fight [an arrest]."