HOUSTON — When Angela Ochoa arrived at her fiance’s hospital bed, he was unconscious.

“He had cuts to his hands, swelling to his face, to his abdomen. He obviously had to have put up a fight,” Ochoa said.

But no one could tell her what had happened.

Later that day, Nov. 19, Border Patrol Agent Rogelio “Roger” Martinez died.

No one can tell Ochoa what happened to the man she was to marry.

Agents in the Border Patrol union say he was assaulted by rock-hurling migrants.

President Donald Trump and other officials held up his death as example of the dangers faced by the Border Patrol and as another reason to build a wall on the border.

But last week the FBI said it had found no evidence of an attack; it offered no further explanation for Martinez’s death.

Ochoa continues to await answers. She said that on the last night of his life, Nov. 18, Martinez sent her a text at 10:30 p.m.

“He was letting me know he was going to be out and about — that they were sending him out,” Ochoa said.

Martinez, 36, was working along Interstate 10 about 120 miles east of their home in El Paso.

He had just radioed the nearest Border Patrol station to say he was checking a sensor that had been activated in a concrete culvert frequented by migrants and drug smugglers.

Fellow Agent Stephen Garland, at a gas station a dozen miles away in the nearest town, Van Horn, was summoned to assist Martinez.

Soon after, Garland, 38, called his wife on his cellphone, disoriented. She alerted the station in Van Horn that he and Martinez were in trouble.

Garland then spoke with a dispatcher, saying he wasn’t sure where he was, but that the two were hurt and had run into a culvert.

The agents were found in the 9-foot-deep culvert. Both were still wearing their utility belts.

An autopsy released last week found Martinez died of “blunt-force trauma,” but how he received his injuries remains unclear.

His manner of death was ruled “undetermined.” U.S. Customs and Border Protection Commissioner Kevin McAleenan sent a memo to agents late Wednesday that revealed more.

“The absence of evidence is a key factor in this case — not due to lack of effort or determination, but because evidence which would indicate the presence of other persons or the commission of a criminal act is not present,” the memo said.

McAleenan wrote that the FBI had found no evidence the agents were attacked, and noted further evidence indicating an assault by smugglers was unlikely.

“There were no defensive wounds on Agent Martinez or his partner who suffered injuries in this incident, and there was no third-party blood or DNA evidence recovered from the scene or from the agents’ clothing,” the memo said.

No footprints were found at the scene except those of the agents and first responders, the memo said.

The memo said Agent Garland, 38, “fell” about 22 feet from Martinez, “landing on his back and sustaining significant injuries to his back and skull.”

“His resultant injuries have impaired the agent’s ability to recall the events of the incident,” the memo said.

Brandon Judd, president of the union that represents agents, the National Border Patrol Council, took issue with the memo and insisted the agents were attacked.

“In that area drug smugglers use booties to disguise their footprints,” he said. “The problem right now is there is no evidence of an attack, a vehicle accident, or a fall. And I would argue that where Agents Martinez and Garland’s bodies were a fall is just not likely.”