If a person is arrested (God forbid) on Shabbat what leniencies, if any, should he be aware of? For instance may he sign paperwork (with a shinuy) or have his fingerprint taken if refusing to do so would lead to significant legal repercussions?
Resisting arrest in America is always pikuach nefesh. If you are able to explain to the police your needs and they are helpful, then maybe you can avoid melacha without resisting. But any resistance could easily lead to an over zealous officer firing his weapon or inflicting life threatening harm. Whenever a persons power to enforce his will on you comes from a gun, then that is pikuach nefesh.