Sounds more like a public shaming than vigilante justice.
In the old west the vigilance committee would have done a lot more than threaten criminal thugs. Although the thugs now understand that the entire community knows who they are, is watching them, knows where they live, and dislikes them very much. In such a situation self imposed banishment is probably the best course of action for the young thugs.....or finding Jesus.
“Tar and Feather” “Run out of town on a rail” and, oldest of all, “Outlaw” all have real and useful meaning, and can be appropriate vigilante alternatives to “String them up.”
In the costal community where I grew up, the creative alternative of sending people out to sea on a log in the general direction of Hawaii was allegedly used in one or two instances. Maybe the journey was successful, and the descendant have multiplied.
“Beat the Sh!t” out of them, accompanied by public shaming would seem to be appropriate in this instance.
If the community on an organized basis is unwilling to invest in jails and use them, perhaps they can invest in stocks. They were cheap and likely more of a deterrent than some things used today.
“or finding Jesus.”
…Let’s pray they choose “or”