Men who were traveling with Carmelo Cruz Marcos, a 32-year-old Mexican migrant who was shot and killed by a Border Patrol agent in southern Arizona earlier this year, told investigators that the agent and his colleagues appeared to tamper with evidence and concoct a cover story following the fatal incident.

After months of silence in the case, the Cochise County Attorney’s Office announced on Monday that it had insufficient evidence to bring charges against the Border Patrol agent, Kendrek Bybee Staheli, for the February shooting and that the agent’s actions appeared justified under Arizona self-defense laws. Late Wednesday night, the Cochise County Sheriff’s Department, the lead local agency that investigated the case, released a 28-page file that formed the basis for the prosecutor’s decision.

In an interview with authorities, Staheli described fearing for his life during his encounter with Cruz, claiming that Cruz picked up a rock as he attempted to take him into custody, causing the Border Patrol agent to open fire. Staheli’s partner, who did not witness the fatal encounter, said Staheli was distraught after killing Cruz and asked to be held.

Migrants who Cruz was traveling with, later interviewed by county officials, provided a more chilling version of events, with one claiming that the agents appeared to move Cruz’s body after he was killed and that Staheli’s partner told him things would be fine so long as Staheli said he was scared and that Cruz threatened him with a rock.

The case has sparked outrage in Mexico, with Cruz’s family alleging that the father of three was “assassinated” by U.S. border agents. In an interview last month, an attorney for the family confirmed that they intended to file a lawsuit in response to the killing.

“We totally condemn the use of violence,” Ricardo Peña, head of the Mexican consulate in Douglas, Arizona, where Staheli and his partner are based, told The Intercept in an interview prior to the announcement that charges would not be filed in the case.

The sheriff’s department investigation also confirmed the role of a controversial Border Patrol crime scene response unit, known as a Critical Incident Teams, in the case. Last week, the commissioner of Customs and Border Protection announced that the teams, which operate borderwide, were being disbanded after years of allegations of tampering with investigations and evidence in cases involving the deaths of migrants.

In a press release last month, demanding an independent investigation, Karns and Karns, a Los Angeles-based law firm representing the Cruz family, said the use of the units reflects a “glaring conflict of interest.”

“My husband was a gentle and peaceful man trying to provide for his family,” Cruz’s wife, Yazmin Nape Quintero, said at the time. “He would never threaten the Border Patrol, and it is despicable for the Border Patrol to claim that he did. We seek to clear his name, and we seek justice so other families won’t suffer like we are suffering.”

The shooting occurred in a rugged corridor of the Peloncillo Mountains known as Skeleton Canyon on the night of February 19. Cruz was traveling with a group of at least nine other migrants. They wore the camouflage and carpet booties common among migrants traversing the region.

Staheli, who joined the Border Patrol in 2019 following a 10-month stint as a police officer in Utah, was assigned to the agency’s mounted unit, known as the horse patrol. Staheli’s partner, Tristan Tang, is a seven-year veteran of the agency.

Four days after the killing — Border Patrol agents, according to the sheriff’s report, are not allowed to speak with local authorities within 72 hours of a killing — Staheli, with his lawyers present, gave an interview to county investigators. Staheli told them he and Tang were looking for signs of unauthorized border crossers along Geronimo Trail Road when they received a radio call alerting them that a sensor had picked up migrants in the area.

The agents headed in the direction of the sensor. The terrain became rough, so they dismounted and continued on foot. Eventually, they came across the migrants, who fled.

The two agents had apprehended three of the migrants when Tang, with night vision goggles, spotted a fourth in Staheli’s area. According to Staheli’s account, he was between 70 to 80 yards from his partner when he closed in on the migrant. When Staheli reached the fleeing migrant, the report said, the man “turned around and through [sic] a punch at him with a closed fist.”

Staheli told investigators that the man in front of him was shorter than he was but appeared to outweigh him and that he was wearing an “older army style camo” that, in his mind, indicated that he was working for a Mexican drug cartel and thus likely to put up a fight. According to his autopsy, the man in question, Cruz Marcos, was 5 feet, 4 inches tall and weighed 159 pounds.

Staheli claimed that Cruz’s blow glanced off his shoulder and struck him in the jaw. He tackled Cruz to the ground and “told the subject to place his hands behind his back but he failed to comply.” Efforts to pry Cruz’s arms out from under him were failing, Staheli said. As the two grappled, Staheli said he grew worried that Cruz could have a weapon or that his companions might attempt to rescue him, so he began punching him in the face repeatedly. The continuous blows caused Cruz to become “very upset,” the report said, and he managed to buck Staheli off his back.

According to Staheli, Cruz then picked up a rock “seven to ten inches long, oval shaped and bigger than a soft ball,” and cocked his arm back like he was preparing to throw. Staheli told investigators that he thought he was going to die. “He said he then drew his service pistol, pointed it at the subject and fired,” the report said. “He said he fired more than once. He said he fired many rounds but could not recall how many.”

An autopsy confirmed that Cruz was shot four times, twice in the face and twice in the chest. He also had bruising on his right cheek and neck and a cut on his scalp.

After the shots were fired, Tang called out to see if his partner was OK. Staheli yelled back that he was fine. Tang rushed to the scene and told his partner to stand back while he attempted to provide medical care to the man on the ground.

“Agent Tang saw lots of blood,” the report said. The man was lying on his back with “multiple holes” in his body and clearly dead. “Agent Tang then focused back to Agent Staheli to ensure he was still okay,” the report said. “He asked Agent Tang to hold onto him, so he hugged him.”

“Agent Tang said they waited approximately 2 hours for other agents to arrive at their location,” the report said. “He did not talk anymore about the incident with Agent Staheli.”

In Staheli’s account, one of the migrants in custody asked him if he had just killed a man. Staheli confirmed that he had and when the migrant asked why, he said, “Because he tried to kill me.” The migrant warned the agent that he would not sleep well that night, “that he was nervous and shaking and that his spirit was going to follow him, that he would haunt you for the rest of your life, you better watch your back.”

Cruz’s body was removed from the scene the following day. “Although the exact rock which Agt. Staheli described as being used by Carmelo was not recovered many rocks were noted in the area and photographs of the scene were taken which clearly show the rocks,” county investigators noted. “Based off of evidence at the scene, trajectory and angle of shots fired into Carmelo’s body, and statements taken from the agents and witnesses it appears Carmelo was the aggressor in this incident.”

Cochise County detectives interviewed some of the men who were with Cruz the night that he died. Filomeno Ruiz-Martinez recalled little beyond the flash of lights and the English-speaking agent who told him to raise his hands. His companion, Irving Torres Peralta, had more to say.

“He said he observed four lights, he said he remembered three of the people he had crossed with had been apprehended, he said one of those subjects was his brother,” the report said. “He said when they were apprehended he could hear a male subject say in the English language, ‘This is America motherfucker.’”

Torres told investigators that he understood English and that he heard the words while he was hiding with Ruiz-Martinez.

The report noted that Torres attributed the words to Staheli but cast doubt on the veracity of the claim because Ruiz-Martinez did not mention hearing the same thing. Ruiz-Martinez, however, also told investigators that he does not understand English.

Investigators asked Staheli if recalled saying “You are in America motherfucker” before killing Cruz. The agent said he did not.

Carlos Juan Torres-Peralta, brother of Irving Torres-Peralta, was also questioned. Before his interview began, he asked the investigators in Spanish, “Are you going to kill me too?”

Torres-Peralta described being set upon by agents on horseback. One of the agents dismounted, he said, and yelled, “This is America.” That agent also said to his companion, “Stop or I’m going to shoot you.” Torres-Peralta said his companion tried to run away but tripped on a rock. When the agent caught up with the man, he said, “This is America motherfucker.” According to the report, Torres-Peralta was referring to Staheli.

“He said then he heard Agent [Staheli] say, ‘You’re in America motherfucker’ and he heard shots fired,” the report said. Torres-Peralta said he saw the flash from Staheli’s service weapon.

“He said he didn’t see anything but believed both agents went to look at his companion and they moved his companion’s body,” the report added. The investigators noted that Torres-Peralta “did not describe what happened prior to what he believes were the agents moving the body.”

Investigators were confused by Torres-Peralta’s claims: “If he had not seen them how could he have made the determination they were moving his companion’s body.” Torres-Peralta went on to say that he heard Staheli’s partner tell him not to talk to anyone. “He said he heard the other agent tell Agent [Staheli] again, don’t worry man, don’t talk with no one and it will be fine,” the report recounted

Horaldo Jimenez-Cruz, who was also interviewed, said he was already in custody when Staheli opened fire and saw nothing of the incident. Ricardo Huerta-Nepomuceno said the same.

Investigators conducted follow up interviews with the Torres-Peralta brothers and the other men, noting that “for the most part that four of the subjects statements were some what consistent with regards to the information they initially provided.” Carlos Torres-Peralta, however, added additional information, telling investigators that after Staheli took him into custody, he told him, “Shut up or I will shoot you.”

The investigators observed that Torres-Peralta was far more fluent in the English language than he initially appeared. He again said that he believed the Border Patrol agents moved Cruz’s body and that he “heard them discussing how they should follow up with statements and not say anything to anyone, and that Agent Tang had told Agent Staheli ‘it would all be ok and that he had his back.’”

“Carlos further said he heard Agent Tang tell Agent Staheli that he should say he was attacked with a rock,” the report said. “Carlos statements would suggest the agents had covered up evidence and would not be truthful with any after action interviews they would have.”

In a letter to the sheriff’s department on Monday, county attorney Brian McIntyre said Staheli’s actions in the Cruz case “appear to be justified under Arizona law,” noting that law enforcement officials can only use lethal force in those instances in which they feel that they — or another person — are facing a deadly threat.

McIntyre added that in Arizona, those officials are afforded the same self-defense protections as anyone else in the state. In Cruz’s case, McIntyre said, there was not only “insufficient evidence” to contradict Staheli’s claims, “Indeed, the evidence appears to support the Agent’s version of events.”

Last month, Dan Karns, lawyer for the Cruz family, flew to Mexico to meet with Cruz’s family and surviving children. In Cruz’s home state of Puebla, Karns found growing outrage over the case, which for many has come to symbolize the systematically brutal treatment of migrants on the U.S.-Mexico border.

“They’re pissed,” Karns told The Intercept. “Just the undignified behavior of Border Patrol, consistently, over and over and over again, people are getting really upset in Mexico and who can blame them?”