Across:
1 Ombudsman dismisses bad (‘Ombudsman’ dismisses ‘bad’ = omusma = SUMMON) call (SUMMON),
4 No longer locked up for a crime perhaps (ABSOLVED), as sailor (Able-Bodied seaman = AB-) found the key (-SOLVED) (ABSOLVED),
9 Cheat (cheat) criminal (= anagram indicator) (cheat = HECAT-) from Spain (-E) (HECATE), the mythological one synonymous with dark places (HECATE),
10 Keep it out of the papers (bury = BUR-Y), coming to grips with piece (-GUN-) on Old Penny (-D-) (BURGUNDY) – the one that’s drunk in France (BURGUNDY),
12 Detectives (DIs = DI-S) arresting father (-RECTOR-) (DIRETORS) working on the board (DIRECTORS),
13 Mother of Pearl (NACRE) and Caroline fails to get oil (‘Caroline’ fails to get ‘oil’ = carne = NACRE),
14 Keeping an eye out (LOOKING) for Len’s (GLASS) (LOOKING GLASS) copy of The Mirror, for example (LOOKING GLASS),
18 Current (electric alternating current = AC-) bank (-HILL) is (IS-) on grounds (-LAND) (ACHILL ISLAND) surrounded by water that one needs Michael Davitt to get to? (use the Michael Davitt bridge to get from mainland to ACHILL ISLAND),
21 Ohio sacked by hooligans (‘Ohio’ sacked by/removed from ‘hooligans’ = lgans = SLANG), in a manner of speaking (SLANG),
22 Local gave someone a Rocket (locally “gave someone a rocket” = TICKED OFF) scratched from the list (TICKED OFF),
24 Brings to court (ARRAIGNS) two artists (RA+RA), one who is retiring (= reverse indicator) (RA = AR + RA = ARRA-), to sign (sign) compromise (= anagram indicator) (sign = -IGNS) (ARRAIGNS),
25 Duck (-O-) in basin (basin) swimming (= anagram indicator) (basin = B-NSAI) (BONSAI) by small tree (BONSAI),
26 Figure out (DISCOVER) of nightclub (DISCO-) upsetting (= reverse indicator) minister (Rev = -VER) (DISCOVER),
27 A problem for the traveller (JET LAG) from Spain (-E-) heading to (heading ‘To’ = -T-) Lima (L-) in expensive car (J- -AG) (JET LAG).
Down:
1 Timetable (SCHEDULE) for outbuilding (shed = S-HED-) around college (-C-) and university (University of Limerick = -UL-) getting energy (-E) (SCHEDULE),
2 A (-A-) top Clos (top ‘Clos’ = -C-) in Burgundy (burgundy = M-AROON) (MACAROON) produces something with a biscuity flavour (MACAROON),
3 Tricky (= anagram indicator) topic (topic = OPTIC) for one employed in the pub (OPTIC)
5 Capital (BRUSSELS) near Chantilly, for example (Chantilly LACE) (BRUSSELS LACE), with a famous fabric with a raised design (BRUSSELS LACE),
6 Part of the body (ORGAN-) giving university awards (firsts = 1sts = -ISTS) (ORGANISTS) to church musicians (ORGANISTS),
7 Check for accuracy (vet), clip (t) (‘vet’ without ‘t’ = VE-) on the Mediterranean coast (-NICE) (VENICE) or on the Adriatic (VENICE),
8 Something for someone who won’t be patient at night (DAYBED) in the guest quarters (DAYBED),
11 Gold in (gold in) ground (= anagram indicator) (gold in = LONG DI-) with view (-STANCE) (LONG DISTANCE) covered by one familiar with Marathon (LONG-DISTANCE runner),
15 Anonymously (INCOGNITO) and illicitly copy (-COG-) popular (in = -NI-) review (= reversal indicator) dividing teachers (Irish National Teachers’ Organisation = INTO = IN-TO) (INCOGNITO),
16 Our Alec’s (Our Alec’s) novel (= anagram indicator) (Our Alec’s = CAROUSEL) situated in JFK’s milieu of high-flyers, for example (CAROUSEL in JFK airport),
17 Providing intelligent directions (EDIFYING) to engineer (E-) on last legs (dying = -D-YING) going around island (-I-) and starting to flag? (starting to ‘Flag’ = -F-) (EDIFYING),
19 Most (t) of the bias (slant) (‘slant’ without ‘t’ = -SLAN-) in papers (ID papers = I-D) (ISLAND) in Ireland, for example (ISLAND),
20 On reflection (= reverse indicator), looked (saw = WA-S) around address (online address = url = -LRU-) (WALRUS) for a close relative of SEAL (WALRUS is a relative of ‘eared seal’),
23 Gradually destroy (ERODE) drugs (E+E = E-E) found on both sides of bar (bar = -ROD-) (ERODE).