A jihadi cannot have a criminal record and still be a jihadi? To make a case for it being a "criminal acting alone", you must supply at least a plausible criminal motive for the attack.
In the absence of such a motive, the only motive that remains is a jihad response to yesterday's honor killing convictions.
Update: Liege press conference confirms lone attacker, Nordine Amrani, killed three and injured 75
See also about the pan-Arab pan-Islamic Bin Laden glorifiers: AEL, Arab European League. at my post: