BREAKING: Van runs down several pedestrians in London

[chimp3]

It's quite tragic to blame a religion that calls for peace explicitly:

Sura 8, Page 184, The Quran:
( 61 )   And if they incline to peace, then incline to it [also] and rely upon Allah. Indeed, it is He who is the Hearing, the Knowing.

Sura 5, Page 113, The Quran:
( 32 )   Because of that, We decreed upon the Children of Israel that whoever kills a soul unless for a soul or for corruption [done] in the land - it is as if he had slain mankind entirely. And whoever saves one - it is as if he had saved mankind entirely. And our messengers had certainly come to them with clear proofs. Then indeed many of them, [even] after that, throughout the land, were transgressors.

Why aren't these verses brought up whenever a mass murder is carried out by a terrorist who claims he understood and read the Quran fully?

Because the verses that preach violence are more fitting to describe violent behavior.

Quran (2:191-193) - "And kill them wherever you find them, and turn them out from where they have turned you out. And Al-Fitnah [disbelief or unrest] is worse than killing... but if they desist, then lo! Allah is forgiving and merciful. And fight them until there is no more Fitnah [disbelief and worshipping of others along with Allah] and worship is for Allah alone. But if they cease, let there be no transgression except against Az-Zalimun(the polytheists, and wrong-doers, etc.)"