Per local reports, cops say 21-year-old Mitarius Boyd -- who's reported to have been working as the team lead on Wednesday when this horrific incident unfolded -- shot 34-year-old Travonsha Ferguson while trying to stop what he says was an active theft in progress.

Boyd reportedly told investigators that he fired his weapon at both Ferguson and another woman she was with after pursuing them to their car ... where he claims they were trying to unload a bunch of stuff they'd allegedly just jacked from inside the Walgreens.

According to him, he felt his life was in danger when one of the women started to spray him with mace -- as he says he didn't know if they had a dangerous weapon on them. In other words, he's claiming self-defense here ... and has not been arrested at this point.

Cops say Ferguson -- who's reported to have been 7 months pregnant -- was hit 8 times ... twice in each leg and four times in the stomach. She and her friend made it into the car after the gun went off, and the friend is said to have dropped her off at the ER on her own.

Doctors attended to her immediately, and she underwent 3 surgeries. During those procedures, reports say an emergency C-section was done to take out the baby ... who was miraculously not hit during all this. Both she and her child are now in critical condition.

The case is under investigation, and the D.A. is reviewing the Walgreens employee's claim -- namely, that he had to shoot in order to protect himself from imminent danger.