Help, what should i do about my dogs?

my 3 dogs dug a hole under the fence and got out, the killed a small dog and now they want to sue us (so much for being neighborly -_-) its not the first time they got out, so they already have an offense. my dad wants to get rid of the dogs, but we don't know what to do or the process of impounding a dog and the cost. so yeah...... what should i do now