  We examine resonant slepton production at the LHC with gravitinos in the
final state. The slepton undergoes gauge decay into a neutralino and a lepton,
the neutralino decays into a photon and a gravitino. By measuring the
transverse masses of the gamma- G and the l-gamma- G subsystems it is possible
to accurately reconstruct both the slepton and neutralino masses. In some
regions of parameter space the slepton decays directly into a lepton and
gravitino, giving an identical experimental topology to W production (l missing
E_T). We present the novel matrix element squared for lepton-gravitino
production. A peak in the tail of the lepton-missing momentum transverse mass
distribution of the W provides a signature for the process and an accurate
measurement of the slepton mass. We display the search reach for the LHC and
300 fb^{-1} of integrated luminosity.
