Find trashed pages by any parent

Hello,

we currently have the following issue: We are collecting all the pages beginning at a specific starting point (parentId). By using the ContentService/CqlSearchService it is possible to achieve this. Just the trashed pages are missing here.

Is there any way to include the trashed pages? I checked the database and saw that after a page is deleted the parentId in the database is set to null. So I cant even get them using this way.

Do I really need to store the parentId somewhere else in case of a PageTrashedEvent or anything?

Any suggestions for an easy solution?