MISSION, Texas — An immigrant woman, her daughter and another girl who said they were kidnapped and assaulted by a border patrol agent were in the process of surrendering to the agent when their ordeal began, another Border Patrol agent and a federal law enforcement official said Friday.

Agent Esteban Manzanares, who officials say committed suicide early Thursday morning, is accused of driving the three away from the river after they surrendered and assaulting them. The other agent said Manzanares cut the wrists of the adult woman, assaulted one teenager in the group, and then fled the area with a second teenage girl.

The Honduran embassy in Washington, D.C., said the three are a mother, her underage daughter and another girl not related to them. The FBI has said the three were in the country illegally.

The woman who had escaped the attack and walked further upriver tripped a camera at the border fence shortly after 5 p.m. Wednesday, the agent and law enforcement official said.

They said in the camera image a woman can be seen walking toward a gap in the fence. The border agent said there was blood covering her wrists. Within ten minutes of the camera image being taken, agents responded to the woman and began the search, the border agent and federal official said.

The federal law enforcement official spoke on condition of anonymity because the official was not authorized to talk about the case because the FBI was leading the investigation. The border agent spoke on condition of anonymity because the agent was not allowed to speak to the media because of the ongoing investigation.

Customs and Border Protection, the federal agency of which the Border Patrol is part, has said that when they found the woman she told them she had been attacked by a man. The federal official said the woman described the man as wearing green fatigues. Border Patrol agents wear green uniforms. She also described a vehicle that the federal official said authorities believed to be a Border Patrol vehicle.

One of the teenagers was found near the border, and the second girl was located in Manzanares’ home in Mission.