A jury convicted an Adams County man of first-degree murder on Thursday over a 2016 stabbing that took place in a Family Dollar.

Anthony Dennis Grayson, 51, was convicted over the Sept. 1, 2016 stabbing death of Alejandro Alvear at the dollar store located in the 7000 block of Pecos Street in Denver, according to a news release from the 17th Judicial District Attorney’s Office.

Grayson stabbed Alvear, the manager of the store, multiple times during an argument between the two, according to 9News. The argument began when Grayson set off an alarm while leaving the store after making a purchase.

Witnesses inside the store said that Grayson demanded money back from Alvear and threatened to stab him if he refused, the office said. Alvear was sent to Denver Health Medical center where he was later pronounced dead.

“This was a senseless act of violence in a public setting that cost a man his life,” said 17th Judicial District Attorney Brian Mason in the release. “Thanks to the excellent work of law enforcement, eyewitnesses, and our prosecution team, we were able to secure justice for Mr. Alvear and his family.”

As a part of the first-degree murder conviction, Grayson faces a mandatory sentence of life in prison without parole, the office said. The case was delayed multiple times because of issues surrounding Grayson’s competency, but he was found competent enough for the case to move forward.

The prosecution was led by Senior Deputy District Attorney Tim Twining and Deputy District Attorney Stephanie Sickler, both of the 17th Judicial District, the office said. Grayson chose to represent himself at the trial.

Grayson’s sentencing is scheduled to take place on July 29.

For more on this story and others, please visit The Denver Gazette’s news partner 9News.