But how are they to go about stopping him, since bullets cannot penetrate the crust?

One bullet hit the officer, but did not penetrate his vest.

One bullet also penetrated the back of the truck and hit the couple's black dog, which was expected to survive.

Nine bullets penetrated the glass door where I was standing.

Was that why knives and bullets didn't penetrate their uniforms?

The rifles are big because the bullet must penetrate so deeply into the bear.

The bullets penetrated her brain, heart and lungs, she said.

They opened fire, but their bullets couldn't penetrate the wall.

Teams must guess the number of objects that a bullet can penetrate.

It was a solid barrier that bullets could not penetrate.