Ernesto Yanez took an oath to serve and protect the City of Rio Hondo.
But the 26-year-old reserve police officer is accused of breaking the law.
Cameron County Sheriff Omar Lucio told Action 4 News that Yanez is at the center of a criminal investigation.
The reserve police officer allegedly left evidence at the scene of a burglary just right outside Rio Hondo city limits.
Sheriff Lucio said a burglary happened around 2 a.m. Saturday.
Deputies reported that tools were taken from a construction project at the victim's home.
Investigators believe that Yanez picked up 22-year-old friend Manuel Manzanares and gave him a ride to the home.
Manzanares allegedly burglarized the home and then they hauled away the stolen goods in Yanez TMs patrol car.
But according to the sheriff, a deputy drove by the property, saw the open gate and went in to investigate.
Deputies arrested Manzanares for the burglary and linked Yanez to the crime after finding a remote control for a patrol car camera at the scene.
Yanez, who lived in Brownsville, resigned from his post at the Rio Hondo Police Department after authorities charged Manzanares.
The Rio Hondo reserve officer was arrested in Houston and now faces extradition to Cameron County.