How do you deal with stray dogs that bite and maul people?

They should be put down if they are that mean. Cause there's a good chance they'll re-offend and hurt someone worse. It happened here with a retired university president, he was kind enough to forgive the dog's owner after getting chewed on and having stitches. The second time it happened a couple years later the victim sued, the dog was put down but it was too late.