Perhaps the cell phone was in the purse that was listed in the SW?
That's what I thought. Pinkorchid was asking the same thing I have upthread. I assume that D took hers with her to the hospital. Maybe they never asked for it. It could be that KT's was taken and was not collected by LE. I guess they can look at the records without having to have the actual phone, although, I would want the actual phone too.
I hope LE had the insight to go to the room in the house where D claims she heard footsteps and then have someone walk and/or run downstairs and see what if anything can be heard.