Hallo Dr. The basic constituant of an offence U/s.306 IPC are suicidal death and abetment thereof. Abetment the dic meaning is clear enough. Legally speaking to attract the ingridients of abetment , the intention of the police party to aid or instigate or abet the deceased to commit suiice is necessary
As per Concise Oxford Dictionary 9th Edition P 1393 Suicide is stated to mean as the intentional killing of oneself. Whether the decesaed has acted intentionaly to come under the purview of the word suicide or an act of mentally sick is not sure.
To the best of my knowledge sir, intention is important. So from both the angle of IPC and MHA the police is not guilty os any offence.
Your question is appreciated as it involes always some accademical touch. Thank you for putting such a subject in this forum.