We know there’s always a bunch of FRONTLINE films you meant to see, but somehow missed. Where to start catching up?

We went back through our archives to find the five films that resonated most with viewers this season. We looked at why you watched, what you liked and what you said about them. We’ll post one film every day this week — in no particular order.

Here’s #1: 

Raising Adam Lanza

After the shooting in Newtown, Conn. that left 27 people dead, almost all of them children, there were more questions than answers. To understand what happened, FRONTLINE teamed up with the Hartford Courant to investigate the life of the shooter, Adam Lanza, and the mother who raised him.

“Bravo to FRONTLINE for making my brain bigger,” tweeted Michelle Edmonds, from Little Rock, Ark., who called the film “mesmerizing.”

“Objective and fair reporting — appreciated the absence of sensationalism, angling to blame someone or something — well done,” Kerrie Thompson, another viewer, tweeted.

After the film, we continued to uncover more revelations online. Watch the film below and then read more of what we found, as well as the Courant’s full coverage.

Sarah Childress, Former Series Senior Editor, FRONTLINE