UPDATE: Sheriff Spence told Kiii-TV that Border Patrol agent Javier Vega, Jr., was fishing with relatives when two men attempted to rob them, opening fire on Vega and his family. Vega was shot and killed and his father was shot in the hip.

The two suspects have now been identified as Mexican nationals Gustavo Tijerina, 30, of La Villa, Texas, and Ismael Hernandez, 40, of Weslaco, Texas. They were taken into custody Monday and will be officially booked into jail Tuesday, according to Spence.

He said the suspects have confessed to the crime and he is confident that the two will ”face charges of capital murder, attempted capital murder, four counts of aggravated robbery and tampering with evidence,” according to the news site.

An off-duty Border Patrol agent shot in the chest and killed in an attempted robbery Sunday night begged his father to “keep shooting, dad,” while the agent’s mother picked up a rifle and shot at the fleeing suspects as well, police told TheBlaze.

Federal and state law enforcement officials were questioning two male suspects in the killing of the off-duty Rio Grande Valley Border Patrol and the shooting of his father while the family was on a fishing expedition in south Texas.

A U.S. Border Patrol canine team stands nearby after they helped detain a group of undocumented immigrants near the U.S.-Mexico border on April 11, 2013 near Mission, Texas. A group of 16 immigrants from Mexico and El Salvador said they crossed the Rio Grande River from Mexico into Texas during the morning hours before they were caught. The Rio Grande Valley sector of the border has had more than a 50 percent increase in illegal immigrant crossings from last year, according to the Border Patrol. Agents say they have also seen an additional surge in immigrant traffic since immigration reform negotiations began this year in Washington D.C. Proposed refoms could provide a path to citizenship for many of the estimated 11 million undocumented workers living in the United States. Credit: Getty Images

A U.S. Border Patrol canine team stands nearby after they helped detain a group of undocumented immigrants near the U.S.-Mexico border, April 11, 2013 near Mission, Texas. (Getty Images)

Willacy County Sheriff Larry Spence told TheBlaze the suspects are Hispanic and were apprehended five hours after the shooting, hiding in a shed behind the home of a man living in the area. Law enforcement are investigating whether the men are in the U.S. legally.

Police have not released the name of the agent, but said it does not appear the suspects knew he was a member of the Border Patrol.

Spence said it appears that the agent, his two young children, a young friend and the agent’s parents were fishing together. The suspects had made several passes along the road by the water when they spotted the group, and approached the victims and told them to get on the ground. The suspects were surprised when they discovered that the off-duty agent and his father were armed, Spence said.

“We’re still putting the pieces together but it doesn’t appear now that they knew he was a Border Patrol agent,” Spence said. ”The Border Patrol agent apparently kept telling his dad to ‘keep firing, dad, keep shooting, dad’ at the suspects after he was already hit.”

At some point, the agent’s mother “apparently picked up the AR-15 rifle and continued shooting at the suspects’ vehicle, hitting the windshield and other parts of the vehicle as the suspects fled.”

Spence said police believe the suspects tossed their weapons as they fled in their vehicle after the shooting.

The sheriff said police had spoken with one family member by phone and were waiting to interview the rest of the family members who were at the scene.

Spence said the FBI, Texas Department of Public Safety and a number of other outside law enforcement agencies have offered their help with the case. Spence said the outpouring of help has been “appreciated because we have limited resources and because it’s a fellow law enforcement officer, it’s all the harder.”

Border Patrol spokesman Joe Guiterrez would not comment on the shooting except to say the incident is under investigation.

A Department of Homeland Security official told TheBlaze they are “looking to see if the suspects are in the United States illegally.”

Willacy County District Attorney Bernard Ammerman, the Texas Ranger Division and the county’s chief investigator have all been involved in questioning the suspects, Spence said.

“Based on what has been found at the crime scene it appears that there was a shoot-out,” Spence said. “The suspects’ vehicle, which was found several miles from the crime scene, was shot at and apparently broke down after the suspects fled.  Police investigators are in the process of getting a search warrant to open the vehicle.”

A number of robberies that fit the same pattern have been occurring in Cameron County, which borders Willacy County, Spence said.

“We’ll be looking at the various robberies and if any more people are involved, we will find them,” Spence said. “If there is a connection we’ll find it, and it will be a big relief to the people in our communities if we put an end to this.”

Spence, who has been the county sheriff for 29 years, called the situation heartbreaking.

“I called out a prayer asking the Lord, help us resolve this and five hours later, we found the individuals,” Spence said. “It was nice that we had the assistance from numerous federal and state law enforcement agencies and divine help. Prayers go out to the family of this tragic crime. I can’t imagine what the family is going through at this time.”

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