Authorities investigating the suspicious deaths of eight terminally ill nursing home patients focused Tuesday on the means and motives of two former nurse's aides charged with murder in two of the deaths.

The arrests of Catherine May Wood and Gwendolyn Gail Graham followed a two-month investigation into the deaths at the Alpine Manor Nursing Home in this Grand Rapids suburb.Investigators believed at least some of the eight residents were suffocated in their beds, said Walker Police Chief Walter Sprenger.

Detectives investigated but were unable to confirm allegations that the suspects began choosing their victims based on initials of the victims' names, which they hoped to use to spell the word "murder," Sprenger said.