I don't think there are permission settings for tickets. I think this is a great feature. I'd suggest adding a product idea that would restrict editing and/or deleting tickets based on roles and the ability to report on deleted tickets.
In addition to what
I’ve had this exact problem and have been monitoring deletions using the already suggested Ticket Task Email alert. The issue I’m fining now however, is knowing which user it was. It’s great knowing a ticket has been deleted by can't seem to find a way of including the User name in the email alert task. Is there a solution I may have missed?
I’ve even created a test email alert by selecting every available option within the insert Piped text option {a}.
I’ve even tried various manual inserts (as seen with the top two options within my email body). all without luck.

Any help would be amazing
For those with the same problematic, I found a way to detect who is deleting it's tickets: create an Action with a Ticket Event, and set the trigger to "Ticket Deleted", that way you can then create an Email Task that sends you an email with the username assigned to that ticket.
Is there a way of the email take advising who deleted the ticket rather than it showing the user name assigned to the ticket?
The scenario I have is where all ticket owners assigned to them do not have the access to delete the tickets - only our Brand Admin members do.
I need to be able to see which Brand Admin user deleted the ticket along with the ticket information that was attached to it.
Thanks
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