mumbai it was 40 minutes of terror for passengers of the jaipurmumbai superfast express on early monday as rpf constable chetan singh went around coaches firing from his automatic rifle in all he discharged 12 out of 20 bullets killing four peopleofficials said singh was hotheaded and appeared to have lost his cool the trigger for the incident is still being investigated as are reports of him suffering a mental health breakdownread alsorpf constable guns down senior 3 passengers in running traina railway protection force rpf constable part of a team escorting the jaipurmumbai superfast express shot to death four people early on monday in the running train between vaitarna and mira road stations three of the victims were passengers while the fourth was an assistant subinspector withjourneys cut short on train of terrormumbainalasopara the killing of senior citizen kadar bhanpurwala 62one of the three passengers besides a securityman who were gunned down by an rpf constable on the jaipurmumbai superfast express on mondaysent shockwaves among his neighbours at nalasopara where he was popular bhanpurwala wasjaipurmumbai train shooting if mental health concerns existed rpf constable could plead temporary insanity as defence say lawyersanother counsel pranav badheka said the question that the incident throws up is whether the superiors were aware of the constables situationa couple of hours earlier singh reportedly got into a scrap with some passengers at suratsingh and his colleagues constables narendra parmar and amey acharya and assistant subinspector tikaram meena had boarded the train at surat as an escort team the previous day they had travelled from mumbai as the escort for the dadarporbandar saurashtra express on the return trip they were to stay on board till mumbai central meena 57 headed the teamwhen the train reached valsad singh complained of uneasiness and insisted on getting off his colleagues asked him to rest and took away his weapon the arm1 an assault rifle which is a modified version of the ak47 as he continued to argue with meena on wanting to get off a message was sent to the control room to send another constable to relieve him however a while later singh said he was feeling better and wanted to resume duty constable acharya has told the police that singh had attacked him on the train when he refused to return his rifle later acharya saw singh remove the safety catch on the rifle he said he had tried to calm him downacharya and the other constable went off to patrol other sections of the train while meena and singh were in coach b5 at 515am as the train neared vaitarna station singh pumped four bullets into meena in the same compartment he also gunned down kadar bhanpurwala 62 who was getting ready to alight at borivalifor the next 40 minutes or so singh strutted across several coaches with the weapon he crossed five bogies to reach the pantry car where he killed a second passenger before moving on to s6 where he shot