  The Curci-Ferrari (CF)-type of restriction emerges in the description of a
free spinning relativistic particle within the framework of
Becchi-Rouet-Stora-Tyutin (BRST) formalism when the off-shell nilpotent and
absolutely anticommuting (anti-)BRST symmetry transformations for this system
are derived from the application of horizontality condition (HC) and its
supersymmetric generalization (SUSY-HC) within the framework of superfield
formalism. We show that the above CF-condition, which turns out to be the
secondary constraint of our present theory, remains time-evolution invariant
within the framework of Hamiltonian formalism. This time-evolution invariance
(i) physically justifies the imposition of the (anti-)BRST invariant CF-type
condition on this system, and (ii) mathematically implies the linear
independence of BRST and anti-BRST symmetries of our present theory.
