Sometimes, when someone dies suddenly (i.e. they weren't IMMEDIATELY expecting it), somehow they don't seem to realize it and just keep walking around non-corporeally. For instance, an ex of mine was stabbed to death in the workplace, but she was still there months later to for me to catch in a photo when I went by specifically to try to see if she was lingering/trapped/confused, to inform her of what happened if she didn't know, to maybe help her move on. I believe I accomplished this, though naturally I'll never know for sure.
In the sudden violence sense, and especially in the somewhat novel-to-this-theatre 'insta-killed from a blue sky by a drone you didn't even notice' sense, Eastern/Southern Ukraine is likely already uniquely haunted AF (on top of all the shit that happened mid-last-century there), which from a living perspective can take years to decades to 'die down' without some help in moving on. I'd say "presuming this shit doesn't just all start back up there AGAIN in the interim, of course.", but the next wars are shaping up to be more bot-on-bot, i.e. more humans will probably die unarmed and noncombatant in cities/at home than out in the field so much. But it'll likely still be nearly as sudden, unfortunately.

Stone tape theory working overtime in Ukraine .