The "mastermind" behind a kidnapping case in Cameron County last month has been arrested again, according to the sheriff's office. 

Investigators on Tuesday arrested Cesario Mendiola Jr. on charges of directing activity of a street gang, a first-degree felony. 

The sheriff's office initially announced that investigators arrested Mendiola on Aug. 9, but say he later bonded out. 

RELATED: Sheriff’s office: 3 arrested on kidnapping charges in Cameron County, authorities seeking 3 other suspects  

"In the course of the investigation, CCSO Investigators discovered that Mendiola was the mastermind behind the Aggravated Kidnapping and Aggravated Assault," and an arrest warrant was issued, according to a news release from the sheriff's office. 

Authorities began investigating the kidnapping case out of Brownsville on July 3, after deputies responded to Avenida Katarina and met with a witness who said the victim was taken against his own will and had been assaulted while being thrown inside a vehicle. 

After a day of being held captive, the victim was returned severely beaten and made contact with the sheriff's office, according to a news release. 

RELATED: Cameron County Sheriff's Office arrest fourth suspect in kidnapping investigation  

The sheriff's office announced at the time that it had made three arrests — including Mendiola, Victor Manuel Armendariz and Alejandro Galvan — and were searching for three additional suspects, identified as Magdaleno Perales Jr., Ricardo Guerrero Del Torro and Karen Luna. 

The sheriff's office on Tuesday also arrested a fifth person in the case, Francis Samantha Gudino, on charges of aggravated kidnapping and engaging in organized criminal activity charges. 

The sheriff's office continues to search for Del Torro and Karen Luna. 

The investigation is ongoing.