I feel that it is quite possible he had inside information from a former employee.
Being very familiar with that area, I would say that either the shooter or the driver would have had to be very familiar with the area in order to make a quick getaway. Despite the close proximity to the freeway entrance/exit I don’t think it was a random person who happened to hop off the freeway, search for a business to rob, then hop back on the freeway.
The fact that he spent over 40 minutes in the store is puzzling for sure. If the motive was a simple robbery wouldn’t he have gotten in and out as quickly as possible?
Certainly LE would have thoroughly checked out any former employees, especially ones who may have been disgruntled or fired. What about former employees from other Lane Bryant locations?
Here is my theory on the timeline. Approx 10:08 he comes in store, claims he had delivery. During the next ten minutes or so, RM is probably reading the paperwork and not certain about this delivery. She calls a store to verify. By now it is probably around 10:18. This is when I think he pulls the gun. At this time there is 2 employees and 2 customers. By the time he gets all four in the back, bound with tape and collected all belongings, it is closer to 10:30. Sometime around here, 2 more customers walk in and now he has to get them in the back, bound with duct tape. He fights with CW. By now it is probably around 10:35 or so. He calls his lookout/getaway driver to see where he is. The driver pulls in front of store a few minutes later. Probably tells him there is a cop in the parking lot nearby. As he is getting ready to make escape, he starts wondering to his accomplice what do we do with hostages. RM probably hears this and frantically gets her hands free. Thinking the lives of her and her fellow hostages are in danger, she calls 911. We know the rest of the story. This is just my theory and not based on anything from LE or from witness.