Across:
   1. Criminal thumps nine in retribution (10)
   7. 6 could occur on this, with some cracking (4)
   9. Bog gets strangely full with real big amphibian (8)
  10. Right piece solved in formula (6)
  11. Hide fellow who was sentenced to death in 1967 (6)
  12. Instruments of 6 P.M. dismantled or removed (8)
  13. World leaders in getting latinos or blacks executed? (5)
  14. Big drop in river and some in flotilla fret: a worry on the way back! (9)
  17. Demonstrated gruesome device in which one meets unpleasant end (9)
  22,2dn. Lean curd, the sort of 1 made 16 by 5 (5 3 7)
  24. Main group of swimmers? (6)
  25. Rice dish with offal (I put portion back) (6)
  26. Original graffiti and such hinges on deleting second last bit (8)
  27. Fashion to drop large red spot on eyelid (4)
  28. Mark indicating official correspondence with "L"? (10)
Down:
   2. see 22 across
   3. Is fellow teaching Tibetan Buddhism bad for Asian capital? (9)
   4. Champion with Poles and long legged birds (6)
   5. Main contribution to weight: ham! End mental 6 being restricted by this, for improved constitution (6 9)
   6. Techniques which might extract information... if ridiculous rot's true! (8)
   7. Go over main points of horse turning (5)
   8. Perhaps Washington's type of 1 made 16 by 11 vs 20 in 1972 (7)
  15. Dropping ecstasy - how the rift was fixed right away (9)
  16. You, when you all finally grasp fatal flaw: it's not on! (8)
  18. Result when tried (CV adjusted!) (7)
  20. Large, or giant patch of territory? (7)
  21. Tipsy, cheeky frame of mind? (6)
  23. The finish... passed delight! (5)