MCALLEN, Texas (AP) - Three former South Texas law enforcement officers are to be arraigned on drug conspiracy charges that allege they took money to escort drug loads.

Former Mission police officers Jonathan Trevino and Alexis Espinoza and former Hidalgo County sheriff's deputy Gerardo Mendoza-Duran were indicted last week. They're charged with conspiring to possess cocaine with intent to distribute, and aiding and abetting.

Another former officer, former deputy Fabian Rodriguez, pleaded not guilty Monday.

The four men were arrested in December and are to be arraigned in federal court in McAllen. The indictment says they accepted thousands of dollars in bribes to escort drug loads in a federal sting operation.

Trevino is the son of Hidalgo County Sheriff Lupe Trevino; Espinoza is son of the Hidalgo police Chief Rodolfo "Rudy" Espinoza.