Retrograde in History · 2015

Umpqua Community College shooting

On October 1, 2015, Mercury was mid-loop — retrograde in Libra, tracing backward through 6°08′ of the sign.

WhenOctober 1, 2015♎︎Libra 6°08′Rx windowSep 17 – Oct 9, 2015
Mercury retrograde♎︎LibraWikipedia
The record

American mass shooting event in 2015

More from this window · Sep 17 – Oct 9, 2015

Coincidence, not causation: the date is real and ephemeris-based, but a retrograde window is observed, never blamed. For entertainment, not navigation.