Not a classic case of rampage killer on campus, but sad nonetheless. What's more surprising is that these are kids from rich families. One would think that parents would instill responsibility and accountability while providing comfort and luxury that is rare in India.
It's pretty clear that this whole incident could have been averted had the parents been less casual in safeguarding arms from children.
Police say they believe one of the boys they are questioning managed to smuggle his father's gun into the school and hid it in a toilet.
After school closed for the day, the boy and one of his friends retrieved the gun and took turns to fire five shots at their classmate, killing him on the spot, Mr Lal told the BBC.
The BBC's Jyotsna Singh in Delhi says the dead boy's father is in the transport business and the two boys in detention are the sons of property dealers.
Mr Lal said police would be questioning the parents of one of the boys in custody about the gun.
"Those who are given an armed licence are required to ensure that the weapon is kept in a secure place away from innocent children."
Euro International school in question is located in sector 45 of Gurgaon, one of Delhi's booming satellite towns which is experiencing booming property and business expansion.