Don't take this seriously lol

Aries: the one who's secretly helping the murderer
Taurus: the one that doesn't give a shit about what's happening
Gemini: the detective
Leo: the eyewitness of the murder
Cancer: the one who is blamed
Virgo: the one who is scared af but helps the detective anyway
Libra: the one who is kidnapped to lure victims
Scorpio: the murderer
Sagittarius: the detective's helper
Capricorn: the one who was murdered
Aquarius: the one that was close to the person who was murdered
Pisces: the one who is a suspect but isn't blamed

F to all Capricorns in the comments