By Sarah Dewberry, CNN
(CNN) — Cars came to a screeching stop on Interstate 495 near Washington, DC, after a man stabbed four people in an attack that left a woman and a dog dead on the highway.
The chaotic moment unfolded in Fairfax County on March 1 shortly after 1 p.m. when a Virginia State Police trooper responded to a call about a road rage incident following a car crash, as CNN previously reported.
At the scene, the trooper was met by a male suspect carrying a knife who he then shot in self-defense, the agency said in a statement.
“A trooper got out and immediately shot him — from what I saw, at least two to three times,” an eyewitness, who didn’t want her name used to protect her privacy, told CNN. “At this point, I was screaming and hung up with my cousin. I called 911 as I processed what I was seeing.”
Witnessing a violent and horrific event firsthand may seem rare. However, 64% of adults in the United States have had some form of exposure to in-person gun violence, a June 2025 study found. The report also showed that Black and Hispanic adults face significantly higher risks than White adults.
Moreover, 70% of American adults have experienced some traumatic event at least once in their life, according to the National Council for Mental Wellbeing.
What the driver saw left her deeply shaken. “I was terrified another person was involved, or this was a bigger operation than a deranged person,” said the mother of two, adding that she couldn’t unsee the suspect’s slumped body.
Encountering violence or other harrowing events could leave one struggling in the aftermath, according to experts, who say it’s critical to take steps to process trauma right away.
How to process trauma now
Philadelphia-based trauma therapist Shari Botwin advised people to speak and write about the experience immediately after a traumatic event because it allows them to begin processing what happened.
“As soon as someone has experienced trauma or witnessed something, it is so important to talk,” said Botwin, who has been in private practice for 30 years and is the author of “Stolen Childhoods: Thriving After Abuse.” “Tell the story and tell it every day. Tell three people what you saw, then when you wake up the next day, think about other people you can tell it to.”
Botwin added it’s crucial to describe what you saw, heard, smelled and sensed.
Since not everyone will have access to a therapist, she recommends sharing your story with a partner, best friend or trusted family member.
During the first month after the event, journaling can play a key role in helping to overcome psychological turmoil. Write down words, thoughts or feelings about what happened for 15 minutes each day, Botwin recommends.
“By doing that, what you’re doing is you’re going to ward off the more long-term consequences, which oftentimes, for people, can be post-traumatic stress disorder,” Botwin said.
The woman who witnessed the fatal stabbing said that her company offered her eight weeks of paid leave to process the incident.
“I am in therapy, but I do still have moments that are simple to the average civilian that make me wince and I have to give myself some self-compassion,” said the eyewitness, adding that she’ll stop to take some deep breaths.
Other methods of treatment
Practices such as basic self-care, nutritious meals, sufficient sleep, exercis