The first victim in Kolkata died from injuries to the head in June 1989. Twelve more would die in the next six months as panic gripped the city.
All of the murdered were homeless pavement-dwellers who slept alone in dimly lit areas of the city.
Because the murderer killed victims by dropping a heavy stone or concrete slab, the police assumed that the assailant was probably a tall, well-built male.
However, in the complete absence of any eyewitnesses or survivors, no clear-cut leads were available.
Massive deployments of police in various parts of the city at night were resorted to, and numerous arrests were made.