Ep 7. World's End

In Cold Case season 5 episode 7, titled "World's End," the team investigates the death of a young woman named Rachel, who was found strangled in a park on New Year's Eve in 1999. The case takes on added significance as it transpires that Rachel was a survivor of the Columbine High School massacre in 1998, and as the investigation unfolds, it becomes clear that her tragic past may have played a role in her murder.

The episode begins with the discovery of Rachel's body on the morning of January 1st, 2000. It quickly becomes clear that the murder was a brutal one; Rachel was strangled with her own scarf and left in a park, not far from where she had celebrated the turn of the millennium with her friends the night before. As the team speaks to witnesses and pursues leads, they begin to uncover a number of potential suspects. Rachel's ex-boyfriend is revealed to have a violent temper, and her roommate seems to have had a motive for killing her that has to do with money.

However, things take a turn when the team investigates Rachel's past. It transpires that she was a survivor of the Columbine High School massacre, where she had been shot and injured alongside a number of her classmates. The trauma of this event had left her deeply scarred, and she had struggled with depression and post-traumatic stress disorder (PTSD) in the years since. This leads the team to consider the possibility that her past may have played a role in her murder.

With this in mind, the team begins to dig deeper into Rachel's life. They speak to her therapist, who reveals that she had been struggling in the months leading up to her death, and they track down one of her classmates from Columbine who had been with her when she was shot. This person proves to be an important witness, as they are able to shed light on Rachel's mental state and the challenges she had been facing in the years since the massacre.

As the investigation progresses, the team begins to suspect that someone close to Rachel may have been responsible for her murder. They discover that one of her friends from the Columbine survivor's group had been seeing her in secret, and that the two had been involved in a tumultuous relationship. This person becomes the prime suspect in the case, but as the team delves deeper into their past, they begin to uncover a web of lies, deception, and dark secrets that suggest that there may be more to Rachel's murder than meets the eye.

In the end, the team is able to piece together the events leading up to Rachel's death. They discover that the true motive for her murder had to do with jealousy and revenge, and that her past traumas had played a role in creating a toxic dynamic between her and her killer. The episode ends with a poignant scene in which the team reflects on the tragedy of Rachel's life, and the impact that the Columbine massacre had had on her and on so many others. It is a powerful and emotionally charged episode that explores themes of trauma, resilience, and the terrifying ways in which the past can come back to haunt us.