Video has been released showing the man who made his way around a New Jersey mail with a rifle in hand.
NBC New York reports that five surveillance cameras in the Westfield Garden State Plaza mall caught Richard Shoop prowling the mall around closing time on Nov. 4.
The 20-year-old Shoop was dressed in a black leather jacket and a black motorcycle helmet as he marched around the mall with a .22-caliber rifle, according to The New York Daily News.
A security expert and former NYPD commander saw the video and observed that Shoop "looks very determined."
"He knows what he's doing and what he wants to do," John Cornicello told NBC New York, which also noted that at one point, shots are fired and mall customers and employees in the video appear to cringe, then peer through a doorway in curiosity. They apparently see the gunman and start to run.
Shoop fired six rounds inside the mall, striking an elevator, escalator and several store facades. He was using a Sig Sauer rifle modified to look like an AK-47 that he stole from his brother earlier in the day, officials said.
Authorities said that Shoop was a drug abuser who regularly used Molly, a pure form of ecstacy, according to The New York Daily News.