EAST CHICAGO (CBS) — Home from Afghanistan for just five months, 25-year-old Indiana National Guardsman Willie Cook was gunned down while shielding his two-year-old son.

CBS 2′s Dana Kozlov reports its another case of mistaken identity, with no one in custody.

Two-year-old Antoine Cook uses a toy cell phone to talk to his father. It’s all he has.

“And to know that your 2 year old has to pretend to talk to his dad,” said Laquana Norwood.

On February 2, Cook, was shot and killed while in a car near his grandmother’s East Chicago house where he was taking Antoine for a visit. The veteran was found on top of his little boy, shielding him from the 15 bullets that pierced the car.

” He saved his son he made sure that before he left the last thing he did make sure his son was okay,” said Norwood.

Antoine was hit, too, in the left leg. Another bullet skimmed his right and a third grazed the toddler’s head.

Police believe Cook’s murder was a case of mistaken identity, possible retaliation for another shooting just days before. The couple was planning their wedding, and a future.

“Too come home not even five months later and for your life to be just taken away like that,” said Norwood.

Norwood believes someone knows something and she wants them to speak up.

Incidentally, Sgt. Cook was a member of national guard unit 713, the same unit that lost six members in Afghanistan last year. Cook also has another child.

There is a fund set up to help the family with costs. For more information, go to www.gofundme.com/willie-cook-trust-fund