Crypt Killer (PS1) - With Justifier/mouse controls (No Patch Needed)

Crypt Killer
Initial release date: 1997
Platform: Playstation
Genre: Light gun shooter
Developer: Konami
Publisher: Konami

The best way to play any PS1 light gun games on an emulator is "Mednafen" (Standalone). The Emulator that have the Justifier gun support. Beside Mednafen, Beetle PSX (Mednafen Multicore) of Retroarch also support the Justifier but need a little bit to configure the input buttons.
There's no patch needed. (Patch that makes Guncon as justifier gun)

To change controller
CTRL+SHIFT+1
Keep pressing until you see KONAMI JUSTIFIER on the screen

PS1 Light Gun Games with Justifier compatibility
- Crypt Killer - https://youtu.be/HL_U8JSD_7w
- Lethal Enforcers I - https://youtu.be/4nrmPaX-ZA8
- Lethal Enforcers II - https://youtu.be/U4UXlm567VM