Jack Kevorkian, the doctor jailed for participating in physician-assisted suicides, is expected to be used as an expert witness in a Brunswick pollution case. Kevorkian is expected to provide a written or taped deposition from prison for lawyers of the nearly 200 people suing Allied Signal Incorporated, which formerly owned LCP Chemicals' Turtle River chemical plant. Kevorkian, who is serving out a ten-to-25-year prison sentence in Michigan, did research in the 1970s on mercury and its toxicity.