Effects of region of stress concentration ahead of a running crack in Homalite-100 sheets with a centrally located hole were studied by dynamic photoelasticity. Mode I dynamic stress intensity factors and corresponding dynamic strain energy release rates and crack velocities as well as the corresponding Modes I and II static stress intensity factors, static strain energy release rates and strain energy density factors were determined. As the crack approached the hole, the static Mode II stress intensity factor rose to a peak value of approximately 10 to 25 percent of the Mode I stress intensity factor. The curved crack path appeared to have followed a path of maximum static strain energy release rate or of minimum static strain energy density factor. Our past experiences in dynamic crack propagation problems indicate that, other than local perturbations due to dynamic effects, either of the aforementioned static propagation laws should be the governing factor for the crack path in fracture dynamics.