Perry, who was on the show for three seasons,died in March.
She read the script and immediately said yes.
Doherty expanded on the news, in a touching Instagram post.
Credit: Everett Collection
I am deeply honored to pay tribute to Luke on Riverdale.
The care in which this show takes in honoring his memory is beautiful, Doherty wrote.
Smith will first appear in the second episode of season 4.
Riverdalereturns Wednesday, October 9 at 8 p.m.
ET on The CW.
