  A method for detecting gravitational memory is proposed. It makes use of
ingoing null geodesics instead of timelike geodesics in the original
formulation by Christodoulou. It is argued that the method is applicable in the
bulk of a spacetime. In addition, it is shown that BMS symmetry generators in
Newman-Unti gauge have an interpretation in terms of the memory effect. This
generalises the connection between BMS supertranslations and gravitational
memory, discovered by Strominger and Zhiboedov at null infinity, to the bulk.
