Question with possible spoiler

Terry adopted the identity of someone else and was using his membership record.

My father was Air Force, so we moved around a lot. He was also a ward clerk in the 70's. He says that prior to the 70's the records would reside with the bishop of a ward with a copy sent to Salt Lake City whenever a change was made. During the 70's the whole thing became computerized. If you knew exactly where you were moving to you could have all your records forwarded to your new ward. If you didn't know, as would be the case with a migrant worker like the ones on the construction crew, when you setteled in a place your bishop would write to SLC for your records, using full name, birth date and member ID number if known. This snail mail process sometimes took as much as three weeks(when we lived on Guam, in the south pacific.) With the advances in computers I am certain that it takes much less effort and time to get records. It is unimaginable that a bishop would not be imediately notified that the membership records requested were for a dead person. So for this to have happened the killer had to be an early and excelent hacker.