Critical Study on the Absorbing Phase Transition in a Four-State   Predator-Prey Model in One Dimension
  In a recent letter [Chatterjee R, Mohanty P K, and Basu A, 2011 {\em J. Stat. Mech.} L05001], it was claimed that a four-state predator-prey (4SPP) model exhibits critical behavior distinct from that of directed percolation (DP). In this Letter, we show that the 4SPP in fact belongs to the DP universality class. 
Su-Chan Park
cond-mat.stat-mech