  We give a general analysis of AdS boundary conditions for spin-3/2
Rarita-Schwinger fields and investigate boundary conditions preserving
supersymmetry for a graviton multiplet in AdS_4. Linear Rarita-Schwinger fields
in AdS_d are shown to admit mixed Dirichlet-Neumann boundary conditions when
their mass is in the range $0 \leq |m| < 1/2l_{AdS}$. We also demonstrate that
mixed boundary conditions are allowed for larger masses when the inner product
is "renormalized" accordingly with the action. We then use the results obtained
for |m| = 1/l_{AdS} to explore supersymmetric boundary conditions for N = 1
AdS_4 supergravity in which the metric and Rarita-Schwinger fields are
fluctuating at the boundary. We classify boundary conditions that preserve
boundary supersymmetry or superconformal symmetry. Under the AdS/CFT
dictionary, Neumann boundary conditions in d=4 supergravity correspond to
gauging the superconformal group of the 3-dimensional CFT describing M2-branes,
while N = 1 supersymmetric mixed boundary conditions couple the CFT to N = 1
superconformal topologically massive gravity.
