We study the problem of covariant separation between first and second
class constraints for the D = 10 Brink-Schwarz superparticle. Opposite
to the supersymmetric light-cone frame separation, we show here that
there is a Lorentz covariant way to identify the second class constrai
nts such that, however, supersymmetry is broken. Consequences for the
D = 10 superstring are briefly discussed.