ΔE 34.6, loose: different enough that you should pick on purpose. Magos Purple is noticeably lighter, cooler than Murder Scene.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 35). Magos Purple is noticeably lighter, cooler than Murder Scene.
The same difference applies the other way round: Murder Scene is noticeably darker, warmer.
ΔE is the colour difference between our two swatch estimates: under about 6 is close, over about 15 is loose. Real paints also differ in finish, coverage and how they thin, so test before you commit.
See Murder Scene on the colour wheel See Magos Purple on the colour wheel
All matches: Murder Scene equivalents · Magos Purple equivalents