DALLAS — Agents are calling it one of the largest drug investigations in North Texas history.

Guns and drugs are off the street and millions of dollars in cash has been confiscated.

And one of the 25 people under arrest was already in custody for a drunk driving accident that killed a newlywed couple from Irving.

The Drug Enforcement Agency said the Mexican Gulf Cartel operates an international drug ring. In a nationwide operation, they arrested 500 people and stripped the cartel of nearly $60 million in cash.

In North Texas, agents and police officers found 300 kilos of cocaine, 400 pounds of methamphetamines and 20 weapons — including a grenade.

"It's about money. It's about that pile of cash right there," said DEA Special Agent in Charge James Capra. "We're not putting up with it, and we won't put up with it."

Among the 25 people arrested in North Texas was Uriel Palacios. That name may be familiar because he's charged with driving drunk and killing newlyweds Erika and German Clout on September 1.

The bond for a previous DWI had been lowered months earlier. Dallas county District Attorney Craig Watkins said his office wasn't aware of Palacios' link to a federal drug investigation.

"Hopefully going forward we can learn from it, and and when we do have someone in our custody, to not only look at the crime they committed, but to also contact other law enforcement to determine if they have pending investigations against them," Watkins said.

Investigators say all the men they were dealing have criminal histories and are dangerous.

E-mail rlopez@wfaa.com