Attorney Jose Baez is now representing Shirley Wygal -- whose 32-year-old daughter Rebecca Wingo (above, right) was shot and killed by James Holmes inside the Century 16 Theater in Aurora, CO.
As we previously reported ... Shirley believes the theater is partially to blame for the tragedy claiming the emergency exit doors should have been alarmed, or there should have been security guards posted next to them.
Wygal tells TMZ, "When police came that night with official word, Rebecca's baby asked, 'How did he get in?' Dissatisfied with the answer, she asked again. At just 5 years old, she wants to know how it could happen and so do I. If any entity had an obligation to protect the innocent and did not, then every survivor and loved one left behind must hold them accountable. The first step is a timely and thorough investigation."
She continues, "I've engaged a firm large enough to help us all. I am confident in their expertise and appreciate their making this a priority. Rebecca would love these attorneys. As a mom, she'd want her girls to have the truth. As a daughter, she'd insist I find that truth for them."