You could go for something like 'The Deadly Secret' or 'Murder in the Shadows'. They create a sense of mystery and intrigue.
I think 'Bloodstained Vengeance' or 'The Fatal Deception' would be interesting names. They convey the seriousness and drama of a murder fiction. Another option could be to use a more descriptive title like 'The Night of the Gruesome Murder' to set the tone right away.
Some good names could be 'The Silent Killer', 'Murder in the Shadows', 'The Deadly Secret'. These names create a sense of mystery and danger which are often associated with murder stories.
One could be 'The Shadow Stalker'. It gives a sense of a hidden, menacing figure. Another is 'The Bloodletter', which is quite vivid and implies a violent nature. And 'The Silent Slayer' also works well as it suggests a stealthy and deadly character.
You could use names like 'Detective Blackwood'. It gives an air of mystery and professionalism. Another option is 'Victim Vale'. The alliteration makes it catchy and it clearly indicates a key element of the story. Or 'Murderer Malone', which is a bit more straightforward and can create an immediate sense of intrigue.
You could consider names like 'Shadowbane' for the killer, 'Victim Vale' for the place where the murders occur, and 'Detective Dusk' who tries to solve the case.
Some great character names for a murder mystery might be Inspector Graves. The name 'Graves' can evoke a sense of solemnity and perhaps a connection to death. Then there's the femme fatale - like name of Scarlett Nightingale. 'Scarlett' is often associated with passion and a bit of danger, and 'Nightingale' adds an interesting contrast. Also, consider the name Jack Thorn. 'Thorn' gives the impression of something sharp and potentially harmful, suitable for a suspect or a character with a secret.
How about 'The Lethal Plot'? It gives the impression that there was a pre - meditated plan for the murder. 'The Murderous Intent' is also a good one as it focuses on the killer's state of mind.
Lady Scarlet. 'Lady' adds a touch of elegance and aristocracy, while 'Scarlet' is often associated with mystery and danger, like the color of blood.
For a victim, how about 'Ella Gray'? The name 'Ella' is soft and feminine, which makes her seem more vulnerable, and 'Gray' can add a bit of a dull, tragic undertone. As for a suspect, 'Maxwell Stone' could work. 'Maxwell' sounds strong and confident, and 'Stone' gives an impression of coldness and hardness.
How about 'Spellblade Slayer' for the murderer who uses magic in his killings, 'Enchanted Crypt' as the place of the murders, and 'Wizard Watcher' for the one who tries to stop the murderer using magic of his own.
Pay attention to the details. Describe the crime scene vividly, like the position of the body, any signs of struggle, and the weapon used. And don't forget about the pacing. Start slow to build the background and then gradually increase the tempo as the mystery unfolds, keeping the reader on the edge of their seat.