Criminal Minds is one of the most popular police procedural shows, which centers around a group of FBI profilers who must understand the minds of serial killers in order to catch them. And while Criminal Minds has its fair share of horrifying and scary episodes, other episodes have touched viewers' hearts due to their sad storylines. Agents like Aaron Hotchner, Spencer Reid, and even Emily Prentiss have endured several hardships that have left viewers devastated and heartbroken.

Yet even if most of the saddest Criminal Minds episodes deal with storylines directly affecting the BAU team, sometimes, a few unsubs have also touched viewers' hearts. Whether the justification for their actions is just as sensitive as their crimes or because the unsubs aren't fully aware of what they are doing, their stories can be just as compelling and sad.

10 "Riding the Lightning" Focused on a Mother's Sacrifice For Her Son

Season 1, Episode 14

"Riding the Lightning" is a Criminal Minds episode that moves away from the usual formula and instead focuses on two criminals on death row. Sarah Jean Mason and Jacob Dawes are a husband-and-wife serial killer duo who are about to be executed after being sentenced to the death penalty for their crimes. The BAU goes to prison to interview them and possibly get any more information before they are gone, but things soon take a turn when Jason Gideon realizes Sarah Jean might be innocent after all.

What makes "Riding the Lightning" so sad is the realization that even if Gideon can prove Sarah Jean's innocence, she doesn't want him to. Sarah Jean is also accused of murdering her own son, but Jason Gideon finds her son alive and well, adopted by a caring family. Sarah Jean doesn't want to be released, as she has accepted her fate and feels guilty for not stopping her husband. Sarah Jean doesn't want their history to affect her son's life and instead accepts the death penalty if it means her son will survive and thrive, not knowing about what his parents did. Her sacrifice is one that moved Gideon and viewers as well and one that makes this Criminal Minds episode extremely sad.

9 "100" Turned Aaron Hotcher's Life Upside Down

Season 5, Episode 9

Aaron Hotchner's personal life was a big focus in the early seasons of Criminal Minds, from the birth of his son, Jack, to the struggles in his marriage with Hailey to their eventual divorce. But "100" took things further after making Hotch and his family the target of one of Criminal Minds' most dangerous unsubs, George Foyet. Hotch and Foyet's story was a multiple-episode arc, leading to Hotch's family having to go into hiding. However, Foyet eventually got the upper hand and managed to find Hailey and Jack, and audiences had to watch as Hotch rushed to their aid, but it was too late to save Hailey.

The saddest part about "100" is Hailey's realization that Hotch won't make it in time to save her, and as Hotch and Hailey talk on the phone, with the entire BAU team listening in as well, Foyet kills her. Hotch's suffering is evident and heartbreaking, and as Hotch fights Foyet and eventually kills him, audiences can feel Hotch's own agony through the screen. "100" is easily one of the saddest Criminal Minds episodes and one that changed everything for the BAU as well.

8 "Distress" Showed the Dangers of Traumas Left Untreated

Season 2, Episode 17

"Distress" follows an investigation that quickly turns heartbreaking as the BAU team find out the unsub they are looking for is an army veteran suffering from severe PTSD. Roy Woodridge is a family man who served overseas and now has to deal with the trauma left from the war. After his return, he showed signs of PTSD, being uncomfortable with loud noises and in crowded places, but it got even worse when a building was imploded, and he believed the noise was caused by a bomb.

Roy believes he's back at war and kills innocent people he sees as his "enemies." Roy's family, a friend of his and fellow army veteran, tries to talk to Roy and calm him, and the BAU team eventually finds him. However, a construction worker turns a jackhammer on, and the noise triggers Roy once more and a sniper eventually shoots him, believing Roy was trying to hurt a child. "Distress" ends in a sad scene, as Gideon rushes to Roy's aid and realizes Roy was trying to help the kid, not hurt him. Roy's death could've been avoidable, and his crimes were because of severe trauma and PTSD, making "Distress" a really sad Criminal Minds episode.

7 "Mosley Lane" Made a Parent's Worst Nightmare Come True

Season 5, Episode 16

"Mosley Lane" features a husband-and-wife duo of criminals who abduct and murder children. They've been doing so for many years and even made one of the kids help them abduct other children. The abduction of these children and what the unsubs put the kids through is already sad enough, but "Mosley Lane" is even more heartbreaking after learning about Sarah and her son, who was kidnapped eight years ago.

Sarah believes the latest abduction is connected with her son's, and while no one takes her seriously at first, she's eventually proven right. Charlie, Sarah's son, was abducted and kept alive and is now even forced to help the unsubs when abducting more children. However, Charlie eventually kills one of their captors, saving the other children. There is one kid Charlie couldn't save, though, Stephen. Stephen's parents are at the BAU office when all the children are brought back to their families, and they break down when they realize Stephen is not with them and had died only a day earlier. The sorrow and pain of Stephen's parents as they learn about their son's fate is extremely hard to watch and makes "Mosley Lane" one of the saddest Criminal Minds episodes.

6 "JJ" Made Fans Say Goodbye to a Beloved Character

Season 6, Episode 2

JJ's departure from Criminal Minds took many fans by surprise, as she is one of the most beloved characters. Fans were so upset about the news of JJ leaving that they sent letters demanding that they at least bring her back to give closure to her story. This led to A. J. Cook appearing in the first two episodes of Season 6, providing a storyline for JJ's departure. JJ's forced to take a promotion and go to work for the Pentagon, even though she would much rather stay with the BAU. "JJ" was supposed to be A. J. Cook's final episode in Criminal Minds and her exit left a sour taste for viewers.

"JJ" ends with a bittersweet montage about JJ's time at the BAU and the different moments she shared together with the rest of the team, making for a heartbreaking ending. Luckily, JJ returned for Season 7 due to popular demand and continues to be part of Criminal Minds, but many believed "JJ" would be the last time they would see agent Jennifer Jerau, and that made the episode one of the saddest so far.

5 "Lauren" Put the BAU Team's Resilience to the Test

Season 6, Episode 18

Emily Prentiss wasn't on Criminal Minds from the start, but she quickly won over fans and her team members, becoming one of the most beloved members of the BAU team. However, her past comes back to haunt her, leading up to her facing Ian Doyle, an international terrorist Emily helped put away before joining the BAU. "Lauren" sees Emily being tortured before the BAU team can save her, and it takes things a bit too far, faking Emily Prentiss' death in the end.

While viewers know that Emily isn't actually dead, as they see JJ giving Emily new identities, the BAU team believes Emily is gone, and their pain is evident. And even though fans knew she wasn't really dead, it still meant Emily would have to leave the BAU and, therefore, Criminal Minds. Just like "JJ," "Lauren" made fans say goodbye to a beloved character, not knowing whether they would ever see her again. Thankfully, Paget Brewster returned to Criminal Minds and is now part of the revival Criminal Minds: Evolution.

4 "Zugzwang" Made Spencer Reid Lose a Loved One

Season 8, Episode 12