Authorities are trying to figure out if the two incidents are related. They say that the drug busts themselves are not necessarily uncommon. But the fact that both incidents share so many similarities and that they both happened in the same week -- that, they say, is uncommon.
"It was right here on the feeder road," recalled eyewitness Joshua Proula. "They pulled him right over."
This family still can't believe what they saw last night on Highway 59 at FM 2090.
Proula said, "There must be a lot of money involved in that for them to take the risk like that, you know what I mean?"
Montgomery County constables found 23 pounds of marijuana on an El Expreso passenger bus going from McAllen to Chicago. Two people, who constables say stuffed the marijuana in a luggage compartment, have now been arrested.
"They get creative in the way they try to transport this stuff, and this is just another way of doing it," said Sgt. Ronald Willingham with the Montgomery County Precinct 4 Constable's Office. "They send carriers or people to transport it for them. They use any kind of transportation they can move it north with."
Just four days ago, another El Expreso bus came through the Houston area with drugs on board, also on its way to Chicago. That time, authorities arrested the bus driver after finding one million dollars worth of heroin and cocaine on board.
"Once all this is put together and investigated further, we may come up with some things that have happened that would connect these together," Sgt. Willingham said.
We stopped by El Expreso's headquarters to get its side of the story, but an employee there declined to comment. We later got a statement from the company. It reads, in part: "El Expreso is cooperating with the authorities in their investigation, and will continue to do so."
Gilberto Chapa III and Eva Quintanilla are both facing drug charges in connection with Thursday night's bust.