Wheteher Khalid Masood was a true muslim can be debated but the inspiration for these actions undoubtedly came from what was written in Quran and preached in the Mosques.
I do'nt know, i am right or wrong but my feeling is that after becoming a looser in West's 'survival of the fittest' life, they take shelter in Islam, where supremacy of MAN is believed and they suddenly feel that had their woman were in hizab, they might not have been such a looser. A feeling, may be wrong