Wadda ya mean, next time?
You shoulda did something right there and then.
All talk. No action.
After the fact it's: "Boy, next time yer really gonna get it."
or
Don't make idle threats you know you will never carry out.
or
Do something less violent and within the means of the law, like take a little stroll, and calmly call the authorities, and try and get their licence plate and pics of the oos fish.