. >> reporter: nevertheless, baytieh and sheriff's investigator yvonne shull decided to take anothern a decade after linda's death. >> we went back through every interview that was conducted with every witness. >> reporter: they also went deep into linda's medical records, and found out something very strange had happened during her first hospital stay. >> the nurse came back to the room and found the i.v. bag had a discolored fluid in it, and changed it out. >> reporter: after that discovery, shull learned, linda became seriously ill, ending up in the icu. eventually, she got better and went home. but then, four months later, she was sick again. back in the hospital. and again, something odd occurred. >> at that hospital, the i.v., the port on the i.v. which is where they do injections into, an i.v. was broken. >> reporter: this is a different hospital. >> different hospital, different staff. >> reporter: had someone tampered with those bags? could it have been poison? that was never clear. >> they tested everything. they couldn't tell. >> reporter: normal toxicology tests, normal h