Someone coulda given you a blade. Gotten rid of it after the job was done.

[Sparks says that out loud, but he doesn't even sound convinced of it. The idea of mind control left too many what-ifs.]

Ice... Coulda been some kinda icicle attack, maybe. Somethin' that stabbed the victims, then melted. No weapon left behind.

[It was far-fetched, but a lot of things were possible with magic.]