In a phone call with ABC News Saturday, two days after the the footage was released, Perez, 29, said the teen's family is completely distraught over his death, which has sparked protests in Little Village, where he lived and was killed on March 29.
Officers responding to the neighborhood after reports of gunshots shortly before 3 a.m. that day encountered Adam Toledo and Ruben Roman, 21, police said. Both ran, and the teen was shot following a foot pursuit.
Police initially described the incident as an "armed confrontation." Body camera footage shows an officer yell at him to stop, show his hands and "drop it," then shoot the teen in the chest after he puts both of his hands up. According to the Cook County state's attorney's office, the teen allegedly tossed a gun behind a fence right before he was shot.
In a freeze frame of the footage, it appears Adam may be holding a gun. The shooting took place in less than one second, authorities said.
Eric Stillman has been identified in the original case incident report as the Chicago Police Department officer who fatally shot the teen. He's been put on administrative duty during the investigation.
In a statement to ABC News, Stillman's attorney, Tim Grace, said the officer "was faced with a life-threatening and deadly force situation. All prior attempts to deescalate and gain compliance with all of the officers' lawful orders had failed."
Perez said Adam Toledo's mother, Elizabeth Toledo, is hoping the officer will be held accountable.
"She just wants justice," Perez said. "She just wants his name to be cleared because he did have his hands up when the cop shot at him."
Perez described Adam Toledo as a "kind" and "funny" kid who loved to laugh. She recalled that he would play with her 7-year-old daughter Kaylah's dolls to make Kaylah laugh.
The teen was extremely close with his 11-year-old brother, Anthony, and Perez's 11-year-old son, Jael Cholico, she said.
Jael wrote a letter that he read at Adam Toledo's private funeral and which was buried with his casket, Perez said. In the letter, Jael wrote, in part: "Adam's life was cut down short. Adam would have done great things. I wish Adam would [have grown] old with me and Anthony. ... Our kids would have been best friends. Yes, you may be gone, but you will be forever in our hearts."
Marco Toledo Jr., Adam's eldest brother, remembered the seventh-grader as the "most loving and caring little kid" he knew.
In an email to ABC News, Marco Toledo, 22, said one of his favorite memories of his brother was that when he got his first car, Adam and Anthony would always want to help wash it.
Adam Toledo loved movie nights at home -- some of his favorites were "I Am Legend" and "Cloudy with a Chance of Meatballs," Marco Toledo said. The teen also was a fan of zombie movies.
Marco Toledo just bought a house outside Chicago and was looking forward to having his little brothers over for sleepovers.
"Being the oldest of the boys, I have always wanted better for my little brothers and my older sister," he said.
He said his last memory of his brother is of him "all happy," jumping around as he ate pizza.
Amid the ongoing investigation, Marco Toledo defended his younger brother, saying that he "wasn't a bad kid like everyone says he was."
"Us being little kids, we all made mistakes. Why? Because no teenager and no human is perfect," he said. "No matter what, we all have our flaws and mistakes we have made as kids and still do till this day. No matter what people say, kids will be kids and will make mistakes, but will learn from them -- something my little brother didn't get the chance to do."