Songfacts®:

• Kali Uchis originally wrote this deeply personal ballad when she was a teenager briefly living in her Subaru Forester. She eventually recorded "Killer" as the closing song on her debut album Isolation. The American-Columbian songstress explained why to Pitchfork:
  
  "It was really special to me, because I wrote it on my own when I was really young, with a toy keyboard and a little s---ty microphone. I always held on to it because I felt like there was something timeless about it that I needed to not give away so soon. I'm really glad that I did because I was able to find the right people to contribute to the production so it turned out the way I felt it should - full and lush while still having that old-school vibe.
  
  And any song where you're singing about dying should probably be the end of your album. [laughs] It definitely felt like a place to end that was melancholy and somber - but also still, like, maybe I'm gonna come back to life. To be continued? Let's see."
• The song was produced by Daptone Records' Wayne Gordon, who also helped create another of Isolation's ballads: "Flight 22". Uchis ended up dropping the video for "Loner" around the time they were working together, which Gordon drew inspiration from while working on "Killer."
  
  "I would play that video on mute and I would manipulate the music and make this piece while I was watching that video," he explained to Genius, adding that he was also inspired by the classic David Lynch drama Mulholland Drive. "You feel like doom is right around the corner but you don't know when, but you're pretty much in this dream state the whole time. I wanted to create that feeling with that song."
• Another inspiration was film composer Bernard Herrmann, best known for composing the music for many of Alfred Hitchcock's movies. "With a song like 'Killer,' you want to make it as, I won't say whimsical, but you don't just want to straight go psycho with it," Gordon said. "The subtle sarcasticness, musically Bernard Herman is great at that."