  We compute the scattering amplitudes of four massless states for chiral
(closed) bosonic and type II superstrings using the Kawai-Lewellen-Tye ($KLT$)
factorization method. The amplitude in the chiral bosonic case is identical to
a field theory amplitude corresponding to the spin-$2$ tachyon, massless
gravitational sector and massive spin-2 tardyon states of the spectrum. Chiral
type II superstrings amplitude only possess poles associated with the massless
gravitational sector. We briefly discuss the extension of the calculation to
heterotic superstrings.
