As two masked men dragged her into an unmarked SUV, Andrea Velez tried to focus on details she might later remember – one man’s red shirt, the car’s leather seats, a black backpack inside.

At 9.20am on 24 June in downtown Los Angeles, the 32-year-old was heading into work at a footwear company when the men in gator masks jumped out of their car and started chasing vendors and other people on the street, she recalled. As people fled, Velez froze and held on to her bag.

Suddenly, she recalled, one of the men slammed her to the ground and placed her into his car. The men had “Police” vests, but otherwise were in plainclothes and didn’t identify themselves. She didn’t know why they had taken her.

The men, it turned out, were Immigration and Customs Enforcement (Ice) deportation officers. They were looking to question people about “whether they were lawfully present” in the US, an agent later wrote. Velez is a US citizen who grew up in downtown, not far from the incident.

“They just came out ready to attack anyone,” said Velez, in her first interview since her arrest. “I thought they were kidnapping me.”

A day after her arrest, the Department of Justice charged Velez with assaulting an officer, which could carry a 20-year sentence. The claim was shocking to Velez, who is 4ft 11in and said she had not laid hands on anyone.