Sergio Pinex, 18, was killed as he walked with a friend Thursday morning in the 4100 block of 23rd Avenue in Gary, police said.
Family members say one of the suspects even tried to grab a pair of shoes from one of the victims.
"It is hard because I can't believe my brother is gone," said his sister, Shanika Pinex. "I was just talking to him, just laughing on the phone with him."
Pinex moved to northwest Indiana about a year ago to escape a troubled past in Chicago. He moved in with his cousin, Danyelle Eller, and her family.
"He was helping me with my kids and stuff," said Eller. "He wasn't a bad person."
Pinex decided to take a walk with Eller's boyfriend when two men in a white Cadillac pulled up beside them with a PT Cruiser following behind.
"They got out the car and told them to get down on the ground," Eller said. "They started going in their pockets, checking their pockets I guess for money or anything."
When Pinex refused to get on the ground, the suspects opened fire, hitting Pinex in the head and killing him. Then the two cars sped off.
"That's when we tried to get down the street to see if he was OK," Eller said. "By the time we got down there, he was already gone."
Eller's boyfriend says one of the suspects even tried to take his shoes but when the shots were fired they took off.
"I couldn't believe they did that to him 'cause he didn't bother anybody," she said. "They didn't even know him."
Pinex's family describes the teenager as being very helpful around the house. He was apparently trying to find a job and thinking about enrolling in school. He was excited to celebrate his birthday next Tuesday.
"It is really terrible," said his grandmother, Frances Pinex. "Why did they have to kill him?"
Gary police are hoping Eller's boyfriend, who got a good look at the suspects and vehicles, will help them catch those involved.
"All I saw was a young man who, unfortunately, won't get to see his 19th birthday because he was gunned down," said Corporal Gabrielle King, Gary Police Department.
Gary police say they have no suspects in custody.