COLUMBIA, S.C. — For the last 22 years, Ericka Carter has celebrated her son Evan Gaines' birthday. 

This year, she hosted his 23rd party at the cemetery where he was laid to rest after being shot in March while away at school.

"I miss him so much. That's my baby boy," she said. 

Carter was surrounded by family and friends next to her son's grave. 

With her eyes swelling from tears, and a 'happy birthday' balloon in hand, she gave her birthday speech. 

"My heart, everyday, I cry out for Evan. My life will never be the same and I'm thankful Lord for the faith that you have brought to me. Evan, we love you, happy birthday baby boy," she said.

Then a countdown began.

"One, two, three... release them," she said, and dozens of balloons, including a set that spelled out 'Evan,' flew into the sky. 

Although it was an emotional day, Carter says it was worth planning "to honor him."

Her son was known by many as "Evo," and attended Columbia schools including W. G. Sanders Middle School and W. J. Keenan High School. 

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He died his senior year at the University of South Carolina Upstate with goals of becoming a businessman, sparking an outpouring of support from friends, teachers and others he met. 

Over seven months later, there are still limited details in his case. Authorities say Gaines was found dead at the Campus Edge Apartments, less than a mile away from school. 

His death is being investigated as a homicide and is believed to be an isolated incident. 

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His family prayed for closure on Sunday, as they gathered to celebrate his 23rd birthday. 

"His Mama put him in school to get him out the streets and we just knew when we put him in school that he was in the right place and it just tears us apart that he was going to school and something like this here happened," James Carter, Gaines' stepfather said. "This is a senseless killing that we have a hard time dealing with, but we're going to get through it."

"It's just the knowing that someone is still out there that's responsible for this, so hopefully soon, we'll  have some closure," Carter said. "We're praying, I'm praying everyday. 

Family ask for strength, guidance and prayer as the investigation continues into Gaines' death.