Is there a way to verify who input/edit information in DTMS?

There is a way to narrow it down.
If the inputted information was caught right away, you can check the user logs for every user who last used the permission required in input or edit that information.
The longer you wait, the less likely you would narrow that down to a few or one user.
If you are concerned that the information is erroneous, you can also ask to see the source document: DA 705 for APFT, DA 5500 or 5501 for HT-WT, DA 3595-R for record fire, etc.