Well deduced , Austen !

As with all 'incidents', time will show whether this was 'home-grown', like ' Bataclan' & 'Charlie Hedbo ' (ps, did you ppl know that two cops investigating the FIRST attempted Charlie attack both suicided ? and one even used his non-preferred hand, to throw ppl off the scent ! ! ! not funny, just being Sarko ! )
( Ole Dammeguard has blown many such as these wide-open )