2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/220312We prove the spin-statistics theorem for massive particles obeying braid group statistics in three-dimensional Minkowski space. We start from first principles of local relativistic quantum theory. The only assumption is a gap in the mass spectrum of the corresponding charged sector, and a restriction on the degeneracy of the corresponding mass.21 pages, 2 figures. Citation added; Minor modifications of Appendix AMathematical PhysicsHigh Energy Physics - Theory81T05text