Complex sentence: It was initially reported that the man on the right of the CCTV still, who is at large, was Laachraoui and the man on the left, who died in the suicide bombings, was unidentified.
Split into simpler sentences: It was initially reported that the man on the right of the CCTV still image, who is at large, was Laachraoui. The man on the left, who died in the suicide bombings, was unidentified.