In iOS, where are "Recently Deleted" folders located? (Jailbroken iDevice)

The deleted pictures are going to be in /var/mobile/Media/DCIM/ with the rest of your non-deleted pictures. When you delete a photo, iOS modifies a SQLite database located at /var/mobile/Media/PhotoData/Photos.sqlite to change which album the photo is stored in. Essentially, the photo's album is changed to 'Recently Deleted'. To get a list, you can run this SQLite query which returns a list of all deleted photos (including permanently deleted photos, which you will have to ignore).

SELECT
    (
        "/var/mobile/Media/"
        || ZGENERICASSET.ZDIRECTORY
        || "/"
        || ZGENERICASSET.ZFILENAME
    ) AS "FILENAME"
FROM
    ZGENERICASSET
WHERE
    ZGENERICASSET.ZTRASHEDSTATE = 1
;