President Trump promised in November to bring the killers ofto justice and used his death to renew calls for a wall on the Mexico border. The FBI poured its resources into the investigation, conducting more than 650 interviews and 26 searches. While the president and others used agent Martinez's death to make a political point, the .
It all happened in the town of Van Horn – more than 100 miles from El Paso and about 30 miles from the border, reports CBS News' David Begnaud. Agent Martinez was found dead in November in a culvert located along a quiet interstate – an area that looks like the middle of nowhere.
Martinez was responding to a tripped sensor along a known drug smuggling route. He radioed for backup. A law enforcement source tells CBS News Martinez then parked on the eastbound side of Interstate 10. He turned off his headlights and kept his emergency lights off so potential smugglers wouldn't see him coming.
It was a moonless night. There are no street lights there, so really the only light you have would be a flashlight, or the headlights of a passing vehicle. The source says Martinez was not using night vision equipment. He then ran across the eastbound lane, the grass divider, then the westbound lanes and ran right off the edge of a culvert – about a nine or 10 foot drop – that had no guardrail or barrier to stop him.
Agent Stephen Garland, who arrived after Martinez, may have made the same mistake, running across the interstate and right off the edge. The FBI suspects he fell off at a different point because his blood was found about 22 feet away from Martinez's body. A border patrol dispatcher was able to make contact with Garland after his fall. Despite his injuries, Garland was able to get back to his vehicle and turn on his emergency lights.
At that time, Garland told the dispatcher something to the effect of "we ran into a culvert," or "I ran into a culvert," or "I think I ran into a culvert." The dispatcher wrote in his log, "(he) thinks they ran into a culvert." The FBI found no other foot prints at the scene, no defensive wounds on either men, or DNA belonging to anyone other than the two agents.
More than three months after Martinez's death, his fiancée Angie Ochoa isn't convinced by the FBI's theory. She says Martinez's injuries were too severe to have been caused by a fall. She is also suspicious because toxicology tests found a pain medication – butalbital – in his system.
"Somebody convinced him to take that medication I think. Um, to make it seem like it was an accident," Ochoa said. "At this point, I think it was probably given to him intentionally."
"Even in a normal dose, sometimes there could be some impairment of ability to function, but very little impairment," said forensic pathologist Dr. Michael Baden.
, which states he died of blunt injuries to the head, but classified the manner of his death as "undetermined."
"This is all very typical for a fall, and not for a fight," Baden said.
CBS News has learned that Garland suffered multiple broken vertebrae and a brain bleed. The FBI believes he has amnesia, and he has nothing to do with Martinez's death. They found no evidence of animosity or conflict between him and Martinez.
Despite the FBI's findings, union officials at the National Border Patrol Council call Martinez's death a "heinous attack."
No smugglers were ever found. CBS News asked the White House for comment on this story. It told us no. We called union officials 40 times, left at least 15 voicemails, and sent 10 emails and five text messages. When they finally got back to us, they said the people authorized to talk were unavailable.