Students had been advised to stay indoors in a campus-wide email sent at 8:49 p.m., but the university said it was not on lockdown.
The suspect reportedly fled into the woods.
A search involving Westchester County Police included aviation unit and numerous neighboring police departments was conducted.
Details surrounding the incident continue to be investigated.
Check back to Daily Voice for updates on this developing story.
Click here to follow Daily Voice Armonk and receive free news updates.