Here's a snapshot of what I think was published for the first time in May 2024 (and is usually a UK date but occasionally will be a US or Australian date). 113 titles this month. If I've missed anything or got the date wrong, do please leave a comment.
Please note that, unless specifically mentioned, when a book has differing print and ebook release date, I use the print release date. Translators' names are included where known.
Allan, Claire - The Affair
Arlidge, M J & Julia Crouch - The Wrong Child
Baldwin, Jackie - Murder at Whiteadder House #3 Detective Grace McKenna, Edinburgh
Bell, Alice - Displeasure Island #2 Claire Hendricks
Belshaw, T A - Murder on the Medway #4 Amy Rowlings, 1939
Blómkvist, Stella - Murder Under the Midnight Sun tr. Quentin Bates #8 Stella Blómkvist, Lawyer
Bond, Martha - Murder in the Bay #4 Lottie Sprigg Country House
Brody, Frances - Six Motives for Murder #2 Nell Lewis, Prison Governor, Yorkshire, 1960s
Brook, Lee - The Stalker's Twisted Game #16 West Yorkshire Crime
Buckley, Fiona - To Seize a Queen #23 Ursula Blanchard, an Elizabethan lady
Burrowes, Grace - A Gentleman in Search of a Wife #5 The Lord Julian Mysteries
Calvey, Linda - Faith
Campbell, AJ - Did I Kill My Husband?
Cartwright, Jack - A Secret To Die For #2 DCI Cook, Lincolnshire
Christer, Sam - Jasmine, Rose Petals and Murder (ebook only)
Connolly, John - The Instruments of Darkness #21 Charlie Parker, PI, Maine
Cooksley, Jody - The Small Museum
Creed, Ben - Man of Bones #3 Revol Rossel
Cress, Penelope & Higgs, Steve - Death by Dickens #1 Mike Atwell
Dawson, Mark - Dead of Winter (ebook only) #4 Charlie Cooper
Dixon Helena Murder on the French Riviera 16 Miss Underhay
Ellis, Emmy - Grabbed #4 DI Tracy Collier
Ellis, Emmy - Sunk #5 DI Tracy Collier
Ellis, Emmy - Rhombus #28 Cardigan Estate
Field, David - Unhallowed Ground #1 DCI Mike Saxby
Field, David - The Slaughtered Widow #3 Bailiff Mountsorrel Tudor Mysteries
Flatland, Helga - Toxic tr. Matt Bagguley
Ford, P F - Death in a Skip #8 Slater and Norman
Ford, P F - Death of a Pensioner #9 Slater and Norman
Fraine, A L - An Ill Wind #6 Detective Loxley, Nottinghamshire
Galloway, K T - Vanishing Act #9 O'Malley & Swift
Gardner, Ashley - A Darkness in Seven Dials #17 Captain Lacey, Regency Era
Gardner, Frank - Invasion #4 Luke Carlton, Ex-Special Boat Service commando
Gatland, Jack - Broad Sword #6 Tom Marlowe
Grant, Tracy - The O'Roarke Affair #29 Rannoch Fraser
Greene, Morgan - The Trade
Greenwood, Ross - Death in Bacton Wood #3 DS Ashley Knight, Norfolk
Harris, Theo - Born to Kill #7 DC Kendra March
Harrow, Ruth - The Guilty Girl
Hawkswood, Sarah - Litany of Lies #12 Bradecote and Catchpoll, Worcestershire, C12
Hayder, Mo - Bonehead
Hedgecock, Liz & Harmon, Paula - Murder at Work #5 Booker & Fitch
Holland, Sam - The Puppet Master #3 Major Crimes
Hood, D K - Eyes Tight Shut #22 Detectives Kane and Alton
Hunter, Alice - Bad Apple
Hunter, Evie - The Takedown
Hurst, Daniel - The Family Trip
James, P C - Ramsay and the Smuggling Ring #2 One Man and His Dog, 1960s
James, Peter - They Thought I Was Dead: Sandy's Story #20 Detective Superintendent Roy Grace, Brighton
Jordan, G R - The Esoteric Tear #32 Highlands and Islands
Kabler, Jackie - The Life Sentence
Kinsey, T E - An Assassination on the Agenda #11 Lady Emily Hardcastle, 1908
Kovach, Carla - Her Last Goodbye #15 Detective Gina Harte
Lackberg, Camilla - The Cuckoo tr. Ian Giles #11 Patrik Hedstrom and Erica Falck, Fjallbacka
Lane, Anna Sayburn - Death at Chelsea #3 Marjorie, 1920s
Louth, Nick - The Two Deaths of Ruth Lyle #1 DI Jan Talantire, Devon
Lynch, Rachel - Shared Remains #12 DI Kelly Porter, Lake District
McCleave, Simon - The Llangollen Killings #19 DI Ruth Hunter
McGowan, Claire - Truth Truth Lie
MacIntyre, Colin - When the Needle Drops #1 Mull Mysteries
McLean, Rachel (with Joel Hames) - The Cairn #3 Cumbria Crime
McLean, Rachel (with Millie Ravensworth) - Death at St Paul's Cathedral #5 Diana Bakewell
MacNeal, Susan Elia - The Last Hope #11 Maggie Hope
McPherson, Catriona - The Witching Hour #16 Dandy Gilver, Society Sleuth, 1920s Scotland
McPhillips, Fiona - When We Were Silent
Mackenzie, M R - The Reckoning #5 Anna Scavolini
Madeley, Richard - Father's Day
Manning, Nina - Her Last Summer
Mariani, Scott - The Golden Library #29 Ben Hope, Ex-SAS
Markin, Wes - The Secret Diary of Lacey Ray #8 DCI Yorke
Marsons, Angela - Guilty Mothers #20 DI Kim Stone
Martin, Faith - Murder On the Train #21 DI Hillary Greene, Oxfordshire
Maslen, Andy - The Unseen Sister #2 Detective Kat Ballantyne
Mason, Kelly - A Mystery at Moor House #3 Lady Ellen Investigates, 1920s
Masters, S R - How to Kill with Kindness
Matheson, Nadine -The Kill List #3 DI Henley, London ***
Menuhin, Karen Baugh - The Twelve Saints of Christmas #12 Heathcliff Lennox Investigates
Meyrick, Denzil - The Estate
Mistry, Liz - The Blood Promise #1 Solanki and McQueen, Scotland
Morgan, Phoebe - The Trip
Morrison, Lynn & Radcliffe, Anne - The Missing Diamond #1 The Crown Jewels Regency Mysteries
Morton, Mandy - The Suspicions of Mr Whisker #13 The No. 2 Feline Detective Agency
Mukherjee, Abir - Hunted ***
Myers, Amy - Murder at Tanton Towers #1 Cara Shelly, café owner
Nadel, Barbara - The Darkest Night #26 Cetin Ikmen, Policeman, Istanbul
Nagendra, Harini - A Nest of Vipers #3 The Bangalore Detectives Club, 1920s ***
Nixon, Keith - A Deadly Truth #10 Solomon Gray
Norek, Olivier - Between Two Worlds tr. Nick Caistor
O'Sullivan, Darren - The Night They Stole My Baby
Pastor, Ben - The Venus of Salo #8 Wehrmacht Captain Martin Bora, 1939
Penrose, Andrea - The Thunder of Stones #8 Lady Arianna Hadley, Regency England
Phifer, Helen - The Girls on Floor 13 #3 Detective Maria Miller
Reynolds, Amanda - Her Husband's Lie
Rhodes, Tyler - A Comedy of Terrors #7 Max's Campervan Case Files
Robards, Karen - Some Murders in Berlin
Ross, L J - Death Rocks #21 DCI Ryan
Rowson, Pauline - Death on Board #5 Inspector Alun Ryga, Dorset
Ryan, Chris - Traitor
Shaw, William - The Wild Swimmers #5 DS Alexandra Cupidi
Siciliano, Sam - The Gentleman Burglar #9 Further Adventures of Sherlock Holmes
Smith, Nikki - The Guests
Spencer, Tom - The Mystery of the Crooked Man
Staincliffe, Cath - The Fells #1 Detectives Donovan & Young
Stratmann, Linda - Sherlock Holmes and the Mycroft Incident #7 Early Casebook of Sherlock Holmes
Tay, Tania - The Other Woman ***
Taylor, Marsali - Death at a Shetland Festival #12 Shetland Sailing Mysteries
Torrance, Gaynor - The Boy in the Reeds #7 DI Jemima Huxley, Cardiff
Walker, Fiona - The Village Detectives and the Art of Murder #1 Village Detectives
Walker, Rosie - My Husband's Ex
Wassmer, Julie - Murder at the Allotment #10 Pearl Nolan, Whitstable
Watson, Sue - You, Me, Her
Weston, Kate - You May Now Kill the Bride
Williams, T A - Murder on the Italian Riviera #7 Armstrong and Oscar