Before revision:  We find that the speed of the pinned Chase-Escape front is strictly smaller than the speed of the Eden front when its spreading rate is equal to p and show that it is caused by the prey sites at the leading edge being eaten up by the predator. We study the depinning transition between the two fronts in the model at p= 1. At the depinning point, on a line of length L, the variance of the width of red front increases as L^{\alphaf(t/L^z) where f a scaling function with \alpha\approx 1 and z=1.67} 0.1 .
After revision:  We find that the speed of the pinned Chase-Escape front is strictly smaller than the speed of an Eden front with the same value of p, but with no predators. At p= 1. At the depinning point, on a line of length L, the variance of the width of red front increases as L^{\alphaf(t/L^z) where f a scaling function with \alpha\approx 1 and z=1.67} 0.1 .