Uh sure, wedding w/death. Those ligature marks though would mar a picture perfect open casket funeral. They could have manually strangled her w/rope, then threw away the rope, rather than leave them on the premises and on her person.
The bigger picture IMHO is that a young teenage white male probably watches movies like speed, Ransom, Dirty Harry, can misquote them, allude to their ideas, was thinking attache so said attache rather than briefcase, denying remains for proper burial as a warning they would not have a picture-perfect open casket funeral, uses terms like scanned, electronics, countermeasures tactics b/c he's part of the DOOM and QUAKE subculture (as was Harris and Klebold from Colombine).
I've seen excerpts of those Colombine massacre teenager dudes discuss their fantasy of mass-murder and they even said they hope their killing would be made into a movie one day. That's what I think when I read the RN.