Even 24 hours before killing himself and six members of his family, Shibendu Saha was trying desperately to come out of a state of “depressed amnesia”. His strategy: 193 pages of a popular book that tells people how to overcome obstacles.

However, the book, which enumerates ways to come out of depression, failed to change Shibendu’s mindset.

Investigations have revealed that Shibendu had been reading the book for the past few days, a fact admitted even by maid Soma Das. The bookmark was carefully inserted between pages 192 and 193, and the book was placed on a shelf, where Shibendu would always keep it after a read at night. “For the past few days, Shibendu had told his family that he was trying to find ways to pay his debt and the book could help him solve the problem,” an officer on the case said.

Anuj Sharma, deputy commissioner of police (south), who is overseeing the probe, said the sleuths were trying to find out how even such a “positive” book could not deter Shibendu from his decision to kill his family, including two infants.

The sleuths have been busy reading the book, consulting psychologists and trying to gauge Shibendu’s state of mind over the past few days, in the run-up to the serial killings at the Tollygunge Road address.

The two pages where Shibendu stopped reading dealt with “the body and mind.” The chapter explained how the mind has a negative impact on a person’s body.

The chapter also says that a clear mind can cure many diseases, including heart ailments.

The book, according to the police, is now the only gateway to Shibendu’s mind. “This incident is bizarre and Shibendu’s state of mind would have been impossible to gauge without the book,” said an officer.

Psychiatrists echoed the view, adding that Shibendu was desperately trying to come out of depression, which can be gauged from the fact that he was reading a book known to ward off suicidal tendencies among people.

“He however, could not come out of his state of depressed amnesia,” said psychiatrist Chandra Sekhar Mukherjee.

Shibendu took at least four hours to carry out his sinister operation, a task only those who are suffering from “altered consciousness” can execute, say doctors.

“His state of mind was a result of helplessness and depression and the fact that he had planned the killing at least a day in advance shows that his anxiety and depression lasted for several hours at a stretch, which can happen, but is extraordinary,” said Mukherjee.