See for yourself in the video above from GTA 5 mod maker jedijosh920. Then again, it's possible the cops know exactly what Franklin is holding, and it annoys them to no end, thus, he deserves to be arrested. Yes, I'm the walking, talking female shoe-obsessed stereotype people like to make jokes about. Honestly, I didn't either because I'm not up-to-date on the latest fad unless it involves shoes.
Maybe the cops in GTA 5 think it's some sort of newfangled weapon because they have never seen a fidget spinner which means they have no idea what it is Franklin is holding. If you use a fidget spinner in Grand Theft Auto 5, you'll be arrested because the cops aren't fond of this 'stress revealing' toy that's all the rage.
