The officer said he fired his gun because he had been assaulted, but a neighbor said there were no signs of an attack.
A Border Patrol agent shot and killed a woman who had crossed the border illegally near Laredo, Tex., on Wednesday after the officer came under attack, federal authorities said.
The officer was searching for “illegal activity” in a culvert on a residential street in Rio Bravo, a border town about seven miles south of Laredo, when a group of undocumented immigrants started to hit him with “blunt objects,” United States Customs and Border Protection said. The officer, whose name was not released, fired at least one shot with his handgun, fatally striking the woman in the head.
A woman who lives next door to the site of the shooting disputed the federal agency’s account of the events, saying that the property does not have a culvert and that she did not see any weapons that the group could have used.
“They were on the very corner on that lot where there was a tree,” the woman, Marta V. Martinez, said in an interview Thursday morning. “There was no weapon. They were hiding.”
The confrontation, which unfolded shortly before 12:30 p.m. on an empty lot about a quarter mile from the Rio Grande, came at a time when the Border Patrol agency is under intense pressure from President Trump to crack down on unauthorized immigration.
Ms. Martinez said the gunshot rang out about 10 feet from her house. “I didn’t hear any yelling or ‘stop’ or ‘don’t run,’” she said.
After the gunshot, she ran outside, saw Border Patrol agents swarming her block on Centeno Lane and hit record on her cellphone. She then peered over a chain-link fence to the adjacent lot, she said, and saw an officer flip over a woman’s body.
“She was very young,” said Ms. Martinez, who estimated she may have been 20 years old.
The left side of her face was covered in blood, said Ms. Martinez, who can be heard yelling at the officer in the video.
“Why did you kill that woman?” she screamed at the officer, who did not respond. “You killed her!”
The officer began frantically doing chest compressions on the woman, but Ms. Martinez said it was clear that she had already died.
The F. B. I. is investigating the shooting, the authorities said, and agents on Wednesday spoke with Ms. Martinez and reviewed her videos.
On another part of the lot, which is empty except for a few trees, grass and overgrown weeds, an officer caught three men who were believed to be with the woman. As the officer escorted them away, Ms. Martinez said she heard him say: “See what happens? This is what happens with you people.”
Centeno Lane comes to a dead end at a part of the Rio Grande without a fence, making the area and the street a popular route for people who cross the border. Federal agents often zoom down the street, Ms. Martinez said, chasing after suspected undocumented immigrants.
But in the 20 years she has lived there, she said, she had never heard of a Border Patrol agent fatally shooting someone.
Last year, there were 17 use-of-force cases with firearms by Border Patrol agents, a decrease from 55 in 2012, according to Customs and Border Protection. The federal agency does not identify how many of the episodes were fatal.
