HIGHLAND PARK, Ill. - The mayor of the Chicago suburb scarred by America's latest mass shooting says she was once the alleged gunman's Cub Scout pack leader.
Nancy Rotering tells CNN that she expects 22-year-old Robert E. Crimo III will be formally charged later today.
Rotering also says it's her understanding that the murder weapon had been legally obtained.
Six people were killed and more than two dozen injured when shots rang out in the middle of a Fourth of July parade in Highland Park, Ill.
Video clips posted to social media showed the festivities collapsing into panic as revellers realized they were under fire and scrambled for cover.
The violence erupted just six weeks after a deadly elementary school rampage in Uvalde, Tex., killed 19 children and two teachers.
The confluence of America's birthday and a worsening epidemic of gun violence is sure to conjure a familiar brew of hurt, helplessness and outrage.
"Many years ago, he was just a little boy, a quiet little boy that I knew," Rotering said.
"It breaks my heart. It absolutely breaks my heart."
A statement from Homeland Security Secretary Alejandro Mayorkas described a "celebration of our nation punctured by tragedy," and commended the efforts of local law enforcement.
"The security of our homeland requires more; It requires all of us, together, to address the epidemic of targeted gun violence" with new community-based prevention and intervention strategies.
In a tweet late Monday, Prime Minister Justin Trudeau offered condolences to the victims, their families and the Highland Park community.
They "wanted nothing more than to celebrate their country … but instead had their lives change forever," Trudeau tweeted.
"To the injured, and to the loved ones of the victims: Canadians are keeping you in our thoughts."