You should actually talk to the perpetrators of the APS attack.
The Tehrik-i-Taliban Pakistan (TTP) claimed responsibility for the attack, describing it as revenge for Operation Zarb-e-Azb, the Pakistani military's offensive in North Waziristan that started in summer 2014.
TTP spokesman Muhammad Omar Khorasani said that "we targeted the school because the Army targets our families. We want them to feel our pain.", "Our six fighters successfully entered the Army school and we are giving them instructions from outside," said Khorasani by phone. Khorasani also said "Our suicide bombers have entered the school, they have instructions not to harm the children, but to target the Army personnel. It's a revenge attack for the Army offensive in North Waziristan." Later though the Taliban claimed contrary by putting out a statement saying, "More than 50 sons of important army officers were killed after being identified."
[25][26] The attacks were mainly coordinated by TTP leaders operating in Afghanistan.
[27] According to the Pakistani
Federal Investigation Agency or FIA's early investigations, the group was led by the terrorist, Hussain Mubarak Patel who planned the attacks, accompanied by three
Arabs and two Afghans who spoke
Pashto and were from
Eastern Afghanistan.
[28] Moustafa Seyan Sediqyar was later killed in a drone strike in Afghanistan on 9 July 2016.
[29]
https://en.wikipedia.org/wiki/2014_Peshawar_school_massacre