in my personal opinion it is a justfied act coz qadiani have been declared non muslim. i think by using these tactics they try to deceive innocent ppl and presenting them as a muslim.
ppl who are advocating here that allah knows whats in the heart of a person and its level of iman but it is for the world hereafter. in this world u have to see the actions of the person and person who does not beleive in the khatum nabbawut is no more muslim ........
masjid zarar incident . figthss against aswad bib asna, taliha , sajaha and muslima kazzab in the era of hazrat abu bakar is the clear example that claiming himself nabi is not acceptable in islam. (thogh mirza ghulam taken few other stance like masih and mehdi as well but i dont eant to go into the details)
and i think mirza ghlam ahmed was part of that chain. all school of thoughts after much deliberation agreed upon that the ahmedi are not muslims.
coz quran say
"alfitna tu assuda minnal qatal "
Fitna is worse than murder
so i think the act of the police was justified as it is backed by the law endorsed by the parliment and the ulema of various school of thoughts.
may allah show us right path.