Mark Skipper, 15, and Kasreeyal Hester, 17, were killed Feb. 5, 2016. They were found fatally shot inside a vehicle in the 800-block of Burr Street, police said.
At a baseball field in Hammond, Ind., balloons were released Saturday to remember the teens.
"They were fun loving kids is what keeps us fighting to move on with our lives," said Skipper's mother, Stella Skipper Glidewell.
Skipper's friends remembered his sense of humor and dreams of becoming a professional athlete. He was a quarterback on the varsity football team at Morton High School in Hammond, Ind.
"I was lost. I am still lost. I never expected to lose my little brother who I loved for so long," Skipper's older brother, Michael Skipper, Jr.
Hester's friends said the Gary teen also had dreams of playing in the NFL.
"We all still miss him and love him very much," said Hester's friend, Gerado Gante.
Hester had been out celebrating his birthday with Skipper after picking him up at his home.
It's unclear why the boys were targeted.
Gary police have not made any arrests.
"It's bad enough that he's gone, but it's even worse not knowing who or why," said Hael Glidewell, Skipper's stepfather.