Puzzle time:
Study Girl, a promising engineering student, was killed by one of her own classmates. Detective Anon interviewed the four students in her study group and determined that all were lying except for one.
The detective deduced who killed Study Girl on the basis of the following statements:
a. Neuro: Hiyori killed Study Girl.
b. Vedal: Evil didn’t kill Study Girl.
c. Hiyori: Evil was in the locker room with Neuro when Study Girl was killed.
d. Evil: Hiyori didn’t kill Study Girl.
Who did kill Study Girl?