EL PASO — FBI agents investigating the unexplained death of a Border Patrol agent have turned their attention to two brothers who may be suspects in the case, one of whom has been taken into federal custody on an immigration violation, according to court documents filed this week in New Mexico.
Border Patrol agent Rogelio Martinez's death last month was quickly seized upon by President Trump to reaffirm his case for a wall along the border with Mexico. But the FBI has only said it is treating Martinez's death as a "potential attack" and had yet to determine whether he had died in an accident or under other circumstances.
The documents released this week are the strongest sign yet investigators believe that Martinez was the victim of a roadside beating on Nov. 18. The 36-year-old agent was found with severe head injuries and broken bones at the bottom of a culvert along Interstate 10 in West Texas. He died at an El Paso hospital hours later.
Another agent, whom court documents identified for the first time as Stephan Garland, was found near Martinez with serious injuries and no memory of what happened. Neither officer drew his weapon, initially casting doubt on the possibility the agents came under attack.
Jeanette Harper, spokeswoman for the FBI in El Paso, which is leading the investigation, said officials could say little about the latest court filings because the probe is ongoing.
"We are still in the beginning stages to see if these people are connected to this incident," Harper said in an interview.
But in the court filings, the FBI refers to the brothers, Antonio and Jesus Muñoz, as "the likely perpetrators of the assault."
On Sunday, investigators found fabric with red stains and other discolored clothing after obtaining a warrant to search a 2004 Pontiac Grand Am that transported Antonio Muñoz, and another brother, Daniel Muñoz, on or around Nov. 20.
The brothers denied having a role in the incident and knowledge of what happened to the agents.
Martinez's autopsy report has not yet been completed, the El Paso County Medical Examiner's Office said Wednesday.
Antonio Muñoz was taken into custody by U.S. Immigration and Customs Enforcement on Nov. 30 after admitting to entering the United States illegally. The U.S. attorney's office for New Mexico on Tuesday assigned one of its top prosecutors to Muñoz's immigration case, but it's unclear whether the government plans to file additional charges.
According to the FBI affidavit, an informant told Border Patrol agents that the Muñoz brothers were part of a group that may have assaulted the officers with rocks.
A woman who traveled in the Pontiac with the brothers told investigators she overheard Antonio Muñoz speaking to someone about crossing into the United States with drugs "including methamphetamine and heroin."
The FBI affidavit states that Antonio Muñoz "was likely a drug courier." Court filings show he was deported in 2015. He was taken into custody in Portales, N.M., 280 miles from the site where the injured Border Patrol agents were found, near Van Horn, Tex.
Muñoz is being represented in his immigration case by federal public defender Kari Converse of Albuquerque. She could not be immediately reached for comment Wednesday.
Muñoz was ordered detained without bond Wednesday by U.S. Magistrate Steven C. Yarbrough of Albuquerque, federal court records show. Muñoz waived his rights to a preliminary hearing and a detention hearing.
Yarbrough is the same magistrate who issued the search warrant. Muñoz initially appeared before a federal magistrate in Roswell, N.M., following his arrest on immigration charges Nov. 30. His case was moved to Yarbrough's court in Albuquerque that same day, records show.
The new court filings were first reported by Albuquerque TV station KRQE.
Harper said the FBI continues to investigate leads brought forward by the public and that the agency doubled its reward offer to $50,000 this week.