It's very unlikely they were involved -- they live in Verviers, which is far closer to the German border than Liège is. At any rate, my mother will know, as she's the one that keeps in touch with her side of the family. Do wonder if my uncle's involved at all with the resultant police work, as he's a gendarme.
No, the guy turned himself in. He'd been out drinking and (apparently) seen his victim with his ex-girlfriend. Then he went to get a shotgun, lay in wait and killed him getting out of a taxi. Pretty horrific.