A John Jay College professor has been placed on administrative leave after he tweeted about "future dead cops."

Adjunct economics professor Michael Isaacson had posted on Twitter in late August, "Some of y'all might think it sucks being an anti-fascist teaching at John Jay College but I think it's a privilege to teach future dead cops."

In a statement Friday, the college's president said the tweet was shocking and abhorrent, and Isaacson was placed on leave out of concern for the safety of students and faculty.

Mayor Bill de Blasio and Police Commissioner James O'Neill slammed Isaacson on Twitter on Friday, saying his anti-police rhetoric doesn't represent the school or the families of murdered police officers.

PBA President Pat Lynch called for Isaacson to be immediately dismissed from CUNY.