Wade, a native of Chicago who signed with the Chicago Bulls in July after 13 years with the Miami Heat, posted on Twitter:
Chicago has been plagued by gun violence for years, especially in a few South and West Side neighborhoods. This July alone, there were 65 homicides -- the most that month since 2006.
A day earlier, Wade had participated via satellite in a town hall meeting in Chicago on gun violence hosted by ESPN, along with his mother, pastor Jolinda Wade. Dwyane Wade's charitable organization, Wade's World Foundation, does community outreach in the Chicago area.
Outside the emergency room where Aldridge was pronounced dead, Jolinda Wade clutched her sister and spoke for the family as mourners stood in a circle holding hands and praying. She said she'd participated in the ESPN town hall meeting "never knowing that the next day we would be the ones that would actually be living and experiencing it."
"We're still going to try to help and empower people like the one who senselessly shot my niece in the head," Jolinda Wade said. "We're going to try to help these people to transform their minds and give them a different direction."
It is not the first time Dwyane Wade's family in Chicago has been affected by gun violence. His nephew, Darin Johnson, was shot twice in the leg on the South Side in 2012 but recovered.
Chicago had recorded 381 homicides by the end of July, up 30 percent from the same period of 2015. Its murder rate is higher than the more populous cities of New York and Los Angeles.
Family members are caring for Alridge's baby, who wasn't hurt.