Shoppers in a King Soopers grocery store were hit with unexpected tragedy as a 21-year-old man opened fire on Monday, leaving 10 people dead. The shooting took place in Boulder, Colorado, at approximately 2:30 p.m. The perpetrator came into the store with an assault-style rifle, opening fire and killing those who were unable to find cover or escape through the employee stock area (New York Times).

Supermarket employees say that Ahmad Al Aliwi Alissa shot an elderly man, as well as someone else in their vehicle, before going inside the store. Once police arrived, he engaged in a shootout with police officers. As of Tuesday, Alissa is being treated at the hospital for a leg injury and is expected to be brought to the county jail on murder charges once he has recovered enough (Associated Press).

A motive has yet to be established, but it is believed that Alissa was the only shooter, according to Boulder Country District Attorney Michael Dougherty.

Dougherty went on to state that the suspect had “lived most of his life in the United States,” on the basis of his past encounters with law enforcement. Officials said they had two run-ins with him in 2018 for third-degree assault and criminal mischief. Alissa is also familiar to the F.B.I. because of his ties to a different suspect the Bureau was investigating (New York Times).

The suspect’s mental health is also in question, with his brother telling authorities he may have been suffering from mental illness. He said Alissa’s high school bullies may have contributed to him becoming “anti-social,” and that in recent years, he had become increasingly “paranoid” (CNN).

“He always suspected someone was behind him, someone was chasing him,” said Ali Alissa, the suspect’s brother. “We kept a close eye on him when he was in high school. He would say, ‘Someone is chasing me, someone is investigating me.’ And we’re like, ‘Come on man. There’s nothing.’ … He was just closing into himself…” stated Alissa in the article.

As for the victims, individuals nationwide are demonstrating collective mourning and remembrance.

Gov. Jared Polis of Colorado said in a press conference that his heart ached after the shooting, adding that “The eyes of the nation are on Colorado.”

In Washington D.C., President Joe Biden called on Congress to tighten gun control laws in light of the recent events.

“Ten lives have been lost, and more families have been shattered by gun violence in the state of Colorado,” said Biden.

In the meantime, the President also announced that flags nationwide would be lowered in memory of the victims, as the country mourns together.