In Arizona, we use social media for Silver alerts most often. Those alerts are posted to Twitter by default when the alert is issued. For Blue alerts and AMBER alerts, which are (fortunately) rare, we post to Twitter and also post to Instagram and Facebook. We do allow comments on all of our posts across all platforms and we do not delete posts.
We link to the alert page on our website. This allows us to update the information (corrections, status changes, etc.) since Twitter does not allow editing.
We are not a primary investigating agency for missing persons, only the central repository for the records entered into NCIC/ACIC.