Dash cam video shows Lt. Scott Reneau of Tunnel Hill Police Department pulling over a minivan on Interstate 75.

He says the driver sped past acting very "suspicious."

"The first thing that caught my attention is that the driver put a hoodie over his head as he passed my location. That is odd."

Lt. Reneau usually works to stop drug dealers pulling over people on the highways who are hauling big drug stashes.

He is the only trained officer of this kind between the Tennessee-Georgia border and Atlanta.

As he approached the van he was in for a discovery like none he's encountered. The inside was packed with 16 immigrants from Guatemala and El Salvador.

"As I peered towards the back because I couldn't see through the tinted windows. I saw a van packed full of young Hispanic males and one female."

The driver and passenger in the front were first to get out and go through a series of questions.

The men told Lt. Reneau they were here as construction workers even though no one had I.D. to prove it.

He says the other giveaway was none of the group truly looked the part.

"The clothing didn't match what construction workers wear. The hands didn't match construction workers hands."

The investigation shows the group had been in the country for about a week and someone paid for their transport.

He says each arrest is one step closer to solving the larger problem.

"I think it is impossible to stop it, but you can at least stop the ones that you catch."

 Customs Enforcement will hold the group for processing.

Statistics show more than 2 million victims are involved in human trafficking on any given day.

Atlanta is on the FBI's top 15 cities for trafficking crimes.