Crossing the River Logic Puzzle

Crossing the River Logic Puzzle
River Thames needs to be crossed by Mr. Father, Mrs. Mother, A Thug, A Policeman, 2 dogs and 2 Cats.
There is only one boat, which can carry only two people (or a person and an animal or two animals) at a time. Only the humans (excluding the thug) know how to operate the boat.
The boat must travel back and forth across the river in order to pick up all of the