Is there any way to remotely make a Mac which is powered on – but locked – to go to sleep and/or shut down? If so, how?

Motivation: *[See this question][1]*.

E.g. can I use another *Mac B* to login via screen sharing to *Mac A* even if it's locked, and shut it down? Or can I use some other tool, like a remote Alfred script that can execute in the background even if the target computer is locked?

For this question, we are assuming that I am an administrator and have the login details to the target computer.


  [1]: https://apple.stackexchange.com/questions/243343/prevent-wake-on-lan-when-other-devices-wake-from-sleep-or-get-connected-to-power