To Catch a Killer Ending Explained: Who is the Killer & what Happens to Eleanor and Lammark?

Damián Szifron’s To Catch a Killer is a gripping crime drama about an FBI investigation into a trained sniper killer wreaking havoc across Baltimore. 

Starring Shailene Woodley as Eleanor Falco, a troubled yet intuitive police officer, and Ben Mendelsohn as FBI Special Agent Geoffrey Lammark, the film follows their tense partnership as they hunt a shooter responsible for a deadly mass shooting on New Year’s Eve. 

With expert marksmanship, the shooter kills 29 people across the city, setting off a chain of events that leads Eleanor and Lammark on a high-stakes pursuit. In this article, we will explore what happened at the end of the film and discuss who the killer was.

Plot Overview of To Catch a Killer

The movie begins with a shocking mass shooting across Baltimore, where a sniper kills 29 people in cold blood. As authorities scramble to track down the killer, Lammark, assigned to the case, quickly realizes the shooting isn't an act of terrorism, as initially believed. 

He recruits Eleanor, a local cop with a knack for understanding criminals, to help him. As the investigation progresses, Eleanor’s instincts lead the duo to explore a deeper psychological profile of the shooter.

After several false leads and dead ends, including a botched operation that results in casualties and Lammark's wrongful termination, Eleanor uncovers a crucial clue that leads them to Dean Possey. The killer’s identity, once shrouded in mystery, is finally revealed.

The Killer's Identity and Backstory

Dean Possey’s tragic past and mental state offer key insights into his motives. As Eleanor and Lammark discover, Dean was a victim of his own upbringing. Raised by a father who was a shooting instructor and arsenal keeper, Dean was trained to be a marksman from a young age. 

However, a childhood accident left him severely traumatized, and after being rejected by the army, he spiraled into isolation and resentment toward society. Dean's resentment eventually culminates on New Year's Eve, when the chaos of the holiday triggers his pent-up anger.

His frustration with the capitalist and consumerist world around him, combined with his deep social isolation, drives him to murder. His spree continues at a mall, further escalating the violence until Lammark and Eleanor finally close in on him.

The Tragic Death of Lammark

After discovering Dean's identity, Lammark and Eleanor head to Dean's mother’s house in hopes of apprehending him. However, Lammark’s relentless pursuit of the killer leads to tragedy. Dean, a skilled marksman, shoots Lammark through the window, leaving the FBI agent to die in his mother’s house. Lammark’s death marks a turning point in the investigation, deeply affecting Eleanor and further complicating the case.

Dean’s Final Moments and Eleanor’s Dilemma

As the investigation draws to a close, Eleanor faces a moral dilemma. When she finally confronts Dean, he insists that he has no place in the world and wants to die. In a desperate attempt to stop the violence, Eleanor tries to persuade him to surrender. 

However, Dean’s anger and pain are too deep, and he refuses to listen. In a tense standoff, Dean activates a bomb, killing several officers before he’s ultimately gunned down by police.

Eleanor’s Future: From Cop to FBI Agent

After the killer’s capture, Eleanor finds herself at a crossroads. The mayor and his team try to manipulate her into signing a statement that would cover up their incompetence during the investigation. 

In exchange, they offer her a position as an Intelligence Analyst for the FBI. Despite her past rejections and troubled history, Eleanor knows that her cooperation is essential to preserve her future in law enforcement.

With some hard-fought demands, which include posthumous recognition for Lammark and a full pension for Lammark’s husband, Eleanor agrees to the terms. To Catch a Killer closes with Eleanor starting a new chapter of her life as a Special Agent, leaving behind the case that consumed her—and the man who showed her the way.

To Catch a Killer is now streaming on Netflix.