system
Given the following post, respond as if you're commenting on Reddit:
human
[Harry Potter] Could you splinch/telefrag someone by using a Time Turner?

If your point of arrival in the past happened to be where someone was standing, what would happen?

If you've been standing in the same spot for an hour then travel back one hour, would you telefrag your past self?
gpt
#DO NOT MESS WITH TIME

Ahem.

Time-Turners operate within consistent loops. This is *not* a feature of time-travel itself in HP; it is indeed possible to change time and e.g. erase people from time (though time seems to have some kind of Butterfly Effect immunity; if you give someone's father a condom, they vanish from time, but it doesn't retroactively edit the whole world the way you'd expect from chaos theory) but not with a Time-Turner. 

Clearly, the closed-time-loop function of Time-Turners, whereby you can't change time because it's already happened, is a built-in safety feature of the device itself, and it probably has other safety features. 

Presumably, if you tried to perform a Time-Turn that would kill someone like that, it would fail for timey-wimey reasons, the same way it would if you went back in time and tried to kill your past self, which obviously can't happen because it would cause a paradox: you reach for the Time-Turner and inexplicably keep dropping it, or it breaks in your hands, or you have a heart attack and fall over before you can.