Videos that capture the minutes leading up to and immediately after an Immigration and Customs Enforcement agent fatally shot an undocumented Mexican immigrant in Houston early Tuesday morning show agents aggressively following a white work van and then approaching the vehicle on foot.

Security camera footage from nearby businesses and residences, obtained and analyzed by the Washington Post, provides a nearly continuous, six-minute-long view of Lorenzo Salgado Araujo’s van as he is pursued by federal agents. But the agents were not wearing body cameras, and the videos do not clearly capture the moment an ICE agent fires his gun shortly before 7 a.m. local time — a finding that may complicate any investigation into whether ICE personnel were justified in using deadly force against Salgado Araujo.

The Department of Homeland Security released a statement hours after the deadly shooting saying that Salgado Araujo, 52, had rammed an ICE vehicle and “weaponized” his white work van “in an attempt to run over” a federal immigration officer. DHS did not identify the officer or say how many times he fired but said he did so in “self-defense.”

The videos show federal officers in two unmarked SUVs following him closely, at one point cutting off his van and driving on the wrong side of the street toward it. The videos do not appear to show Salgado Araujo ramming a vehicle, but at times, the van and the SUVs are partially obscured from camera view by buildings and trees.

A DHS spokesperson said the department’s Office of the Inspector General is investigating the agent-involved shooting, and the FBI is investigating “the potential assault on a federal law enforcement officer.” The agency did not comment on the Post’s attempt to confirm the timeline of events.

Harris County District Attorney Sean Teare said the county was collecting surveillance footage and witness testimony to determine what happened.

The videos could provide key evidence to corroborate what transpired. The officers involved in the incident had not been issued body cameras and were not wearing them, according to a DHS spokesperson. Surveillance footage and witness recordings have become key in several shootings over the past year involving federal immigration officers, and in some instances have directly contradicted statements by DHS.

Unlike the shootings of Renée Good and Alex Pretti, two U.S. citizens killed by immigration officers in January, no video recorded by witnesses has emerged so far of Salgado Araujo’s killing.

In a statement Friday, the agency said the officers who followed Salgado Araujo‘s van had seen two similar vehicles weeks earlier on the property of a person suspected of being in the United States illegally. DHS said officers were on their way to that person’s residence when they saw Salgado Araujo’s van. Rep. Sylvia Garcia (D., Texas), who represents the district where the shooting took place, said in a TV interview Thursday that an ICE official told her that Salgado Araujo was not the person sought by agents.

Around 5:50 a.m., surveillance video from outside Salgado Araujo’s home shows him getting into his white van and beginning the drive to work. At some point, he picks up the other three men.

An hour later, the van is captured by a camera as it heads south on Highway 90, driving about 50 mph, according to the Post’s calculations. Two black, unmarked SUVs appear to be in pursuit.

His white van makes an abrupt turn onto another street, followed by one of the two SUVs.

The SUV sticks close to the van, pulling up alongside it. Seconds later, the SUV cuts off the van, and Salgado Araujo veers to the left.

Meanwhile, a second unmarked SUV enters Canal Street and drives onto the wrong side of the road toward the van, which backs up as the SUV approaches. It is not clear in the video whether the van makes contact with either SUV at this point.

The van then drives forward, going back the way it came.

As the van drives slowly away from the SUVs, at least three officers are seen pursuing on foot. It is not clear how close the van came to the officers as it turned, but the Post’s analysis indicates at least one officer was close to the passenger side of the van.

The van rolls less than 200 feet before pulling off to the side. Within seconds, several officers converge on the van. Officers pull out at least one person from the passenger side and put handcuffs on them.

Aftermath video of the scene shows Salgado Araujo on the ground by the driver’s side. Two officers are next to him, one kneeling. They appear to be checking on Salgado Araujo, who is visibly distressed.

According to his family, he had been shot in the abdomen. He later died of his injuries.

The three men who were in the van with Salgado Araujo said a federal officer fired at them almost immediately after exiting his vehicle and that at no point did Salgado Araujo veer in his direction. All three men were arrested and are in immigration detention.

DHS characterized Salgado Araujo as an “illegal alien” from Mexico, but his son told the Post that his father was doing what he could to legalize his status in the U.S.

Salgado Araujo’s death marks the first fatal shooting involving ICE agents since Good and Pretti were killed in separate incidents in Minneapolis in January during an enforcement surge in that city.