You are concerned that a user might have been clearing Windows logs. You want to find out if Windows audit logs have been tampered, so that if they have, you can contact the owner of the account to ensure it was a legitimate action.
Audit log data
How to use Splunk software for this use case
For more great content from the Splunk Education and Training team, check out Splunk How-To on YouTube or sign up for a course. In addition, these Splunk resources might help you understand and implement this search: