  The traditional standard theory of quantum mechanics is unable to solve the
spin-statistics problem, i.e. to justify the utterly important \qo{Pauli
Exclusion Principle} but by the adoption of the complex standard relativistic
quantum field theory. In a recent paper (Ref. [1]) we presented a proof of the
spin-statistics problem in the nonrelativistic approximation on the basis of
the \qo{Conformal Quantum Geometrodynamics}. In the present paper, by the same
theory the proof of the Spin-Statistics Theorem is extended to the relativistic
domain in the general scenario of curved spacetime. The relativistic approach
allows to formulate a manifestly step-by-step Weyl gauge invariant theory and
to emphasize some fundamental aspects of group theory in the demonstration. No
relativistic quantum field operators are used and the particle exchange
properties are drawn from the conservation of the intrinsic helicity of
elementary particles. It is therefore this property, not considered in the
Standard Quantum Mechanics, which determines the correct spin-statistics
connection observed in Nature [1]. The present proof of the Spin-Statistics
Theorem is simpler than the one presented in Ref. [1], because it is based on
symmetry group considerations only, without having recourse to frames attached
to the particles.
