Novel about a red killer and a woman whose drawings come to life

Question

I'm looking for a book I read about a knife-wielding serial killer "dressed" in red who could disappear without a trace.

• Media: Novel

• When I read it: 2012-2016 (new release?)

• Genre: Mystery/horror

• Plot: The novel contains a series of random, seemingly unconnected murders that were all committed by a man in red with a knife. He would appear at the crime scenes out of nowhere, stab people, and then disappear without a trace.

  The protagonist is a woman who can temporarily make her drawings come to life. Her drawings are so realistic that when she drew her dead husband, who died in a car crash(?), he didn't realize that he was dead at first. The husband appeared to retain his memories after every resurrection.

  The woman had recurring nightmares, and the plot twist was that the serial killer came from her dreams. When she was younger, she and her mother(?) drove past a giant man advertising something with a knife. She apparently draws in her sleep and when she has the nightmares, the killer comes to life before disappearing. The killer is red because the nightmares have a red background.
  
  The woman decided to fight the paper killer in a final showdown, and during the battle, her husband died again. Right before he faded away, he shook his head, implying that he wanted to stay dead this time.

• Setting: Some kind of city. One of the crimes was committed on top of a transparent glass walkway between two skyscrapers.

• Characters: Artist woman, her dead husband, and a red serial killer.

• Language: English

• Cover: Something red. Might have been a flower of some kind(?)

• Ruled out: Anything by Stephen King.

Answer 1

Death Mask by Graham Masterton

He appeared as if from nowhere, brutally slashed a man and a young woman in an office elevator, then vanished again without a trace. The woman survived and gave the police a detailed description of the killer's bizarre face, yet the police can find no sign of him anywhere. It's as if he never existed. But now he's killed again. And again. One woman holds the key to his terrifying secret...but how do you stop a murderer who isn't there?