A senior Railway official told news agency PTI that the panel has been asked to submit a report to the board in three week.
On early Monday morning, an RPF constable shot dead his senior and three passengers in two bogies and a pantry car on board the moving Jaipur-Mumbai Central Express near Palghar railway station in Maharashtra, officials said.
Constable Chetan Singh (34) killed RPF Assistant Sub-Inspector Tika Ram Meena and another passenger in B5 coach with his automatic weapon after 5 am. He then shot dead another passenger in the pantry car five coaches away and went on to kill one more passenger in S6 coach, which was the 8th bogie from the B5 coach, they said.
He was nabbed with his weapon later while trying to flee after passengers pulled the chain of the train which stopped near Mira Road station (on the Mumbai suburban network) at around 6 am.
Government Railway Police (GRP) commissioner Ravindra Shisve told the media the exact reason behind the incident was not known yet.