Originally Published: 28 NOV 22 07:13 ET

Updated: 28 NOV 22 19:03 ET

By Mark Morales, Eric Levenson and Kristina Sgueglia, CNN

(CNN) -- The gunman who killed 10 people and wounded three in May in a racist attack at a grocery store in a predominantly Black neighborhood of Buffalo, New York, pleaded guilty Monday to state charges of domestic terrorism as a hate crime, murder and attempted murder.

Payton Gendron, a 19-year-old White man, pleaded guilty to one count of domestic act of terrorism motivated by hate, 10 counts of first-degree murder, three counts of attempted murder and a weapons possession charge in the mass shooting at Tops Friendly Markets on May 14. The charges come with a mandatory sentence of life in prison without the chance of parole.

Gendron wore a red jumpsuit and had his hands cuffed in front of him in court Monday. He answered "yes" or "no" to several questions affirming he understood why he was pleading guilty and, on the individual counts, said the word "guilty." He showed no emotion during the hearing.

The guilty plea ensures there will be no state trial and Gendron will not appeal, defense attorney Brian Parker said afterward.

"This critical step represents a condemnation of the racist ideology that fueled his horrific actions on May 14. Before he is sentenced to life without the possibility of parole on February 15, the surviving victims and deceased victims' family members will all have a chance to address the court, the community and our client directly," he said. "It is our hope that a final resolution of the state charges will help in some small way to keep the focus on the needs of the victims and the community."

Gendron's parents said they remain shocked and shattered over the shooting.

"Our hearts are broken over the devastation he caused to the innocent victims he killed and wounded, their families, and the African-American community in Buffalo and beyond," said Paul and Pamela Gendron in a statement. "With today's plea of guilty, he will be held accountable for his actions."

"We are thankful to the law-enforcement professionals who investigated this case and will continue to provide any assistance we can. We pray for healing for everyone affected."

Erie County District Attorney John Flynn described the attack as a racist hate crime and outlined the timeline of the mass killing.

"In just over two minutes the defendant, with the intent to murder as many African Americans as he could, killed 10 innocent Black people and attempted to kill three others," Flynn said in a news conference after the hearing.

The guilty plea comes six months after Gendron used an illegally modified semiautomatic rifle to carry out the mass shooting. Flynn said he got a letter from the defense a few weeks ago saying the defendant was willing to plead guilty.

The victims, including customers, employees and an armed security guard, ranged in age from 20 to 86. Eleven of the 13 people shot were Black and two were White, officials said.

Social media posts and a lengthy document written by the gunman reveal he had been planning his attack for months and had visited the Tops supermarket several times previously. He posted that he chose Tops because it was in a particular ZIP code in Buffalo that had the highest percentage of Black people close enough to where he lived in Conklin, New York.

The document outlined his goals for the attack, according to Flynn: "To kill as many African Americans as possible, avoid dying and spread ideals."

Gendron also faces multiple federal hate crime charges, which carry the potential for the death penalty, in addition to several firearms charges. He has pleaded not guilty to the federal charges.

Gendron apologized to White man during spree

Flynn on Monday outside court laid out the evidence against Gendron, which was primarily based on surveillance video from the Tops supermarket and from a camera attached to Gendron's helmet that was live-streaming the attack.

Gendron arrived to the grocery store with a modified semiautomatic rifle and targeted people because they were Black, Flynn said. At one point, Gendron pointed his rifle at a White man but did not kill him and said "sorry" because the man was White, "thus further demonstrating the defendant's racially motivated attack," Flynn said.

Gendron shot four people outside the grocery store and nine more inside before surrendering to Buffalo Police officers who responded to the scene, according to the indictment.

New York Gov. Kathy Hochul said following the attack that the AR-15 style rifle used in the shooting was legally purchased in New York State, but was modified with a high-capacity magazine, which is not legal in the state.

The state charge of terrorism motivated by hate, passed in 2020, had never been used before in New York.

"No individual in the history of the state of New York has been found guilty of domestic terrorism charge motivated by hate until today," he said.

He made the case that the gunman had not achieved his goals.

"This racist murderer did not fulfill what he set out to accomplish. He failed. He failed miserably because today this city, this community, is stronger and better than it ever was, and we have shown the world that racism has no part in our community."

Families of victims take issue with hearing

Several families of the victims spoke alongside attorney Ben Crump on Monday and took issue with what they described as the legal system's overly sympathetic treatment of the gunman.

"I was angry how the judge was constantly talking to this (suspect) like he was a little prepubescent sixth grade boy," said Mark Talley, 33, the son of Geraldine Talley. "I was angry that they didn't have him look at the family of the victims' faces that he scarred for life."

Zeneta Everhart, whose son Zaire Goodman was shot in the neck but survived, said the gunman's voice in court sounded "nonchalant."

"His voice made me feel sick," she said. "This country is inherently violent. It is inherently racist, and his voice showed me that because he didn't care. You could hear it in that voice. He didn't care."

Crump said that Gendron -- despite his expected life sentence -- appeared to have achieved his goals: to kill as many Black people as he could, to survive, and to get mass attention for his 180-page document.

"Even though I know this is a step in the right direction in our journey for justice, it still is very painful that the goals that he had set out for, he seems to be accomplishing," he said.

Terrence Connors, who represents the families of seven people who were killed in the shooting and two who were injured, spoke to CNN previously about the suspect's plan to plead guilty.

"This is a remarkable group of families that I speak for," he said. "The tragedy is still heavy in their hearts, but they've turned this nightmare into positive action. From their standpoint, he has become irrelevant to their lives. Their lives have become about making something positive from this horrible tragedy."