2 sisters, in 2nd grade and 4th grade, among dead in mall shooting

Eight victims were killed when a gunman opened fire on shoppers at the Allen Premium Outlets in Allen, Texas, on Saturday.

Here is what we know about the lives lost:

Kyu Song Cho, Cindy Cho and James Cho

Kyu Song Cho, 37, and his wife Cindy Cho, 35, who lived in Dallas, were among those killed, officials said.

Their 3-year-old son, James Cho, also died.

"He usually wore elephant bibs and shirts," his day care teacher told Dallas ABC affiliate WFAA. "He loved elephants."

Elio Cumana-Rivas

Elio Cumana-Rivas, 32, lived in Dallas, according to investigators.

Cumana-Rivas, a native of Venezuela, was the fifth of six brothers, said one of his older brothers, Gregory Smith Cumana. He called Cumana-Rivas a hard worker who moved to the U.S. "in search of the American dream."

"Even if he was angry, he always had that smile and his way of making you see that even if there were problems, you had to keep going," he said.

Christian LaCour

Christian LaCour, 20, an on-duty security guard at the outlet mall, also died in the shooting, his sister, Brianna Smith, confirmed to ABC News.

Allen Police Chief Brian Harvey on Tuesday commended LaCour, who he said evacuated someone to safety and then was shot while "courageously remaining to help others."

"He was a really sweet kid," Smith said. "I'm sad that he's gone."

His mother, Tracye LaCour, asked for privacy, telling ABC News they are praying for the families of the other victims.

Daniela Mendoza and Sofia Mendoza

Daniela Mendoza, a fourth grader, and sister Sofia Mendoza, a second grader, were both killed in the shooting, Wylie Independent School District Superintendent David Vinson said in a statement.

The Texas Department of Public Safety didn't identify the girls by their names but did say two girls, ages 8 and 11, were among those killed.

"Daniela and Sofia were the kindest, most thoughtful students with smiles that could light up any room," their principal, Krista Wilson, said in a statement. "Our hearts are broken and words cannot express how deeply they will be missed."

Daniela and Sofia's mom, Ilda, is in critical condition from the shooting, Vinson said.

"Words cannot express the sadness we feel as we grieve the loss of our students. Our thoughts and prayers are with the Mendoza family, the families of the victims, and all those affected by this senseless tragedy," Vinson said.

"We are not announcing the news to students, as we want our parents to be able to have those conversations," Vinson added. "Every school's counseling team is equipped to support those who may be struggling, so please do not hesitate to reach out."

Aishwarya Thatikonda

Aishwarya Thatikonda, 26, an engineer who lived in McKinney, Texas, was also among the victims, Dallas ABC affiliate WFAA reported.

She was at the mall with a friend, who was injured and hospitalized, a family representative told WFAA

Thatikonda's family plans to have her body sent to India, where her relatives are located, WFAA reported.

ABC News' Miles Cohen, Peter Charalambous and Alyssa Pone contributed to this report.