The gunman who opened fire inside a sprawling New Jersey mall was found dead inside the mall early this morning with a self-inflicted gunshot wound, authorities said.
Authorities identified the suspect as Richard Shoop, 20, of Teaneck, N.J., and said his body was found in a back area of the mall around 3:20 a.m.
Police found his body more than six hours after they said Shoop entered the Westfield Garden State Plaza Mall Monday night and fired his weapon at least six times, Bergen County prosecutor John Molinelli said at an early morning news conference. The gun, described as a modified rifle, was owned lawfully by his brother, Molinelli said.
Police are still sweeping the 2.2-million-square-foot building in Paramus to make sure all shoppers and employees evacuated. About 400 people were still inside the mall when police ordered a lockdown of the entire building.
There have been no other reported injuries at this time.
Shoop, according to Molinell, had a history of drug abuse, and was known to law enforcement in Bergen County. Molinell said Shoop's drug of choice was MDMA, also known as "Molly."
Molinelli told "Good Morning America" that he doesn't believe Shoop intended to injure shoppers or mall employees.
"The mall was closing in about 10 minutes so there were thousands of people and many people just surrounding him and the fact that he shot into the ceiling or randomly at other things, we don't think he went in there with the intent to shoot anyone. We think he went in there with the intent that he was not going to come out alive."
Police found an "ambiguous" note at Shoop's home, according to Molinelli.
"I'm hesitant to say it's a suicide note. It does express that an end is coming. It could have been prison. It could have been what he did last night but it's certainly something that gave his family reason to reach out to us sometime after 10 p.m. last night," Molinelli said.
Bergen County spokeswoman Jeanne Baratta said the first call came in shortly after 9 p.m. that a gunman was inside the mall. Police initially responded to an "active shooter" alert after reports of multiple shots fired.
Baratta said SWAT teams and other police agencies converged on the mall. Authorities swept the mall because they were unsure whether the gunman was still inside. Paramus Mayor Rich LaBarbiera initially said police found one shell casing inside the mall.
Panicked shoppers raced toward the exits or hid inside the mall. Witnesses said they saw authorities running inside the mall with their weapons drawn. The mall was immediately placed on lockdown.
Multiple eyewitnesses said the shooter was armed with some kind of rifle, wearing a motorcycle-style helmet and black clothing.
Kimberly Recchia works at a boutique next to Nordstrom's and said she saw a man dressed in black, pointing a rifle toward the ceiling.
"He was just walking slowly towards our side of the end of the mall. Very calm. Didn't look like he was running or he was in a rush. He was just walking very slowly and calm. He didn't say anything," she said.
Recchia hid in a backroom with her manager when she heard more gunshots.
"He was coming closer and closer. The shots were getting louder and louder, but then after those shots we didn't hear anything else," she said.
Eric Delgado, 20, was shopping with friends inside the mall when he heard a gunshot and saw the gunman. After Delgado saw the gunman, he along with seven others hid in a dressing room for 45 minutes and heard a second gunshot.
"He didn't seem that he wanted to kill anyone because he clearly could of because there were people two feet in front of him that he could have shot at, but he didn't shoot at them. Instead he shot toward the ceiling. ..." Delgado said.
A staging area has been set up near Chili's Grill & Bar for family members to be reunited with anyone inside the mall during the lockdown.
Law enforcement officials have been informed by management of the Garden State Plaza Mall that it will be closed today. No word on when it will reopen.
The Garden State Plaza Mall, about 25 miles west of New York City, has more than 300 retail stores, including Neiman Marcus, Nordstrom, Lord & Taylor, Gucci and Louis Vuitton.
ABC News' Josh Haskell contributed to this report.