Police are not sure if Tatum knew her attacker or if she was is the victim of a random shooting.
The teen was walking alone on Columbia near May Street in Hammond when the shots rang out.
"It's not right. It's not human. Whoever did this has no conscious," said Tracy Martinez, victim's mother.
Tracy Martinez clings to a photo of Sarina Tatum. She's the 14-year-old daughter lost just hours after a gunman's attack. Tatum was shot in the head Wednesday but died last night after lingering in critical condition.
"Right now we're going on whatever people can give us and go from there," said Rich Martinez, victim's stepfather.
Tatum's parents say they knew something was wrong when she didn't come home on time from a friend's house. The girl was found on some railroad tracks less than a mile from her Truman Street address after an officer responded to 911 calls about shots fired in the area. Witnesses tell police they did see a suspect running from the scene.
"The victim possibly had either known the shooter or had some prior involvement," said Lt. Richard Hoyda, Hammond Police Department.
Detectives are also looking at a diary entry Tatum made the day of the attack about trouble she was having with a boyfriend.
Sarina was set to begin her freshman year in high school after being an honor student at Eggers Middle School.
"It's a sad day for all of us to learn that. Her mother is a custodian here in our building and we're a family. It's like losing family," said Barbara Fleming, Eggers Middle School principal.
Tracy Martinez wants something good to come from her tragedy and is allowing Sarina to be an organ donor. Still she struggles with her grief.
"This is not right and not supposed to happen to a 14-year-old girl. She is beautiful and had her future ahead of her. It's just not right," said Martinez.
School resumes next week in Hammond. School officials say they will have crisis counselors to help students deal with this crisis.
Police are asking anyone who has any information about Sarina's attack, to call the Hammond Police Department.