We study to which extent SUSY extensions of the Standard Model can describe the excess of events of 3.0 standard deviations observed by ATLAS in the on-Z signal region, respecting constraints by CMS on similar signal channels as well as constraints from searches for jets and [Formula: see text]. GMSB-like scenarios are typically in conflict with these constraints, and do not reproduce well the shape of the [Formula: see text] distribution of the data. An alternative scenario with two massive neutralinos can improve fits to the total number of events as well as to the [Formula: see text] and [Formula: see text] distributions. Such a scenario can be realised within the NMSSM.