  We calculate all of the form factors for the one-photon, $K_L \rightarrow
\pi^+ \pi^- \gamma^* \rightarrow \pi^+ \pi^- e^+e^-$ contribution to the $K_L
\rightarrow \pi^+ \pi^- e^+e^-$ decay amplitude at leading order in chiral
perturbation theory. These form factors depend on one unknown constant that is
a linear combination of coefficients of local ${\cal O}(p^4)$ operators in the
chiral lagrangian for weak radiative kaon decay. We determine the differential
rate for $\K$ and also the magnitude of two CP violating observables.
