Sunday’s premiere telecast of Casey Anthony: An American Murder Mystery drew 2.9 million viewers in Live+same day ratings for Investigation Discovery, making it the best telecast premiere and best series debut in network history.

The first installment of the three-part series aired Sunday, April 9 from 10-11 PM ET. The final episode airs tonight at 10/9c with interviews featuring Caylee Anthony’s grandparents, George and Cindy Anthony.

Casey Anthony: An American Murder Mystery is a comprehensive look into the investigation and subsequent 2011 trial of Casey Anthony for the murder of her daughter Caylee. The series includes new evidence in the case, insight from closest to the Anthony family and never-before-seen footage of Casey Anthony.

The three-part series is produced for Investigation Discovery by Weinstein Television, American Media and Jupiter Entertainment with Harvey Weinstein, Bob Weinstein, Patrick Reardon, Stephen Land, Allison Wallach, Matt Sprouse, David Pecker and Dylan Howard as executive producers. Pamela Deutsch is senior executive producer for Investigation Discovery.