Derivation of All Symmetries from First Class Constraints and   Quantization in 2+1 Dimensional Supergravity
  The first class constraints in N = 1 supergravity in 2 + 1 dimensions are used to construct a generator of three gauge symmetries (including a local supersymmetry) that leave the action invariant. The algebra of these symmetries closes. This generator is used to quantize the model; a ghost involving both Bosonic and Fermionic components arises. 
D.G.C. McKeon
hep-th