A woman charged in the fatal shooting of a Border Patrol agent in Vermont was indicted by a federal grand jury on Thursday, according to court documents.

Teresa Youngblut, 21, is facing two counts in connection to the death of Border Patrol Agent David Maland, 44, who was killed in a shootout last month on Interstate 91 in Coventry, Vt., near the Canadian border.

The indictment charges Youngblut with one count of using a deadly weapon (firearm) “while knowingly and forcibly assaulting, resisting, opposing, impeding, intimidating, and interfering with an officer and employee of the United States.”

The second count charges her with carrying, brandishing, and discharging a .40-caliber Glock handgun “during and relation to a crime of violence,” according to the indictment.

Youngblut has remained in custody after a federal judge ordered her held indefinitely in connection to Maland’s death.

Federal authorities allege Youngblut was driving a 2015 Toyota Prius hatchback with Felix Bauckholt, a German national, in the passenger seat when Maland stopped the car around 3 a.m. on Jan. 20, according to an FBI affidavit.

When multiple Border Patrol agents approached the vehicle, Youngblut allegedly “drew and fired a handgun toward at least one of the uniformed Border Patrol Agents without warning when outside the driver’s side of the Prius,” the affidavit said. “Bauckholt then attempted to draw a firearm. At least one Border Patrol agent fired at Youngblut and Bauckholt with his service weapon.”

Maland and Bauckholt were both killed during the shooting, officials said.

After the shooting, authorities seized a number of items from the Prius, including a ballistic helmet; a night vision monocular device; a tactical belt with holster; a magazine loaded with cartridges; two full-face respirators; 48 rounds of .380-caliber, hollow-point ammunition; a package of shooting range targets, some already used.

Youngblut was also struck by gunfire and was taken to Dartmouth-Hitchcock Medical Center in New Hampshire.

Youngblut’s parents had reported her missing in May after she moved out of the family’s home in Washington state, taking her personal belongings in duffel bags, including her passport and medical records, according to a police report.

Her parents said they “were concerned that [she] may be being forced to take these actions or that she may be in a controlling relationship,” the report said. They described her as “emotionally immature.”

The killing of Maland appears to be linked to a fringe group of vegan activists on the West Coast whose members have been tied to at least three other slayings, including the murder of a state’s witness in California and the killing of an older couple in Pennsylvania, the Globe has reported.

Youngblut’s fiance, Maximilian B. Snyder, was arrested last month on a separate murder charge in California for allegedly stabbing an 82-year-old man who owned an industrial lot in Vallejo, Calif., where members of the group had squatted years earlier.

The guns allegedly used by Youngblut and Bauckholt in the Vermont shooting were purchased by someone federal prosecutors have described as a “person of interest” in the 2022 slaying of Richard and Rita Zajko in Chester Heights, Pa. The Zajkos’ daughter, Michelle Zajko, has also been linked to the West Coast activist group.

Before he joined the Border Patrol, Maland served in the Air Force and worked security at the Pentagon during the Sept. 11 terror attacks. His family told the Associated Press that he served nine years in the military and worked in the federal government for 15 years.

“He was a devoted agent who served with honor and bravery,” the family said in a statement to the wire service.

Nick Stoico can be reached at nick.stoico@globe.com.