"The doctors' opinion based on the histopathalogical and forensic reports which were received by us late last night, show that it is not a case of murder or culpable homicide," Superintendent of Police Bangalore Rural District, D Prakash told PTI.
Quoting the doctors' report, he said, "Visible injuries noted at the time of post-mortem examination, both external and internal are individually or collectively, not sufficient to cause death."
According to the report, he said, chemical examination revealed the presence of paracetamol to the extent of 27 mg in the blood, which is not sufficient to cause death.
The expert opinion from the pathology department revealed "there is a pathology in the heart, which has started well before the usual age, probably due to hereditary cause".
The doctors' report further says "based on the facts available, opinion as to the cause of death is undetermined".
However, based on the opinion furnished by the pathology department, further examination of the heart may throw more light on the disease of the heart, the report said.
Prakash said the doctors' report shows that it was not a case of murder or culpable homicide, adding "however, further investigation into the case is on".
Nineteen-year-old Richard, a second semester student of Acharya NRV School of Architecture, was found dead on his hostel bed on the afternoon of April 18.
While police initially termed it as a "death under mysterious circumstances", his parents alleged it to be a case of murder.
The death sparked off nationwide protests with students demanding justice for Richard.