They Should Live So Long First edition

In a terrifying series of events, someone is killing older people in nursing homes, for "humanitarian" reasons. But the motive turns to profit when the killer gets money from the next of kin, who are tired of paying exorbitant monthly fees for patient care. Two detectives assigned to the case keep coming up empty. The suspects are many but the results are skimpy. In a harrowing experience of physical struggle, the vital clue surfaces, and the killeris finally revealed.