This story was originally published on Dec. 2. To mark the fourth anniversary of the Sandy Hook school shooting, it is being republished. 
 
 Sandy Hook Promise, an organization devoted to protecting children from gun violence that was launched in the wake of the Sandy Hook Elementary School massacre in Newtown, Connecticut, has issued a powerful public service announcement urging people to look for warning signs of potential shooters. 
 
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 In the Dec. 2 PSA, part of the organization’s “Know the Signs” campaign, viewers are introduced to Evan, a typical teenager, trying to find summer love as the school year winds down. We see Evan scratch “I am bored” into a desk in his school’s library, and he returns the next day to find a response from a female student. 
 
 Evan and the mystery girl scratch flirtatious messages back and forth, and Evan tries to find out who his secret pen pal is. On the final day of school, as yearbooks are being passed around for signatures, Evan’s chat partner recognizes his handwriting and reveals herself. But while she does, an ominous figure emerges through a door in the background, drops a large duffel bag, and cocks an assault rifle. 
 
 Viewers are then shown a shortened version of the same PSA: The message is that while viewers were distracted by Evan’s romance, they neglected the warning signs of a male student in the background who reads gun-enthusiast magazines, searches for gun videos on YouTube, and is bullied in the school’s halls. Towards the end of the PSA, viewers see the male student make a menacing gesture towards his teacher after receiving a poor test grade. 
 
 Text appears in the ad: “While you were watching Evan, another student was showing signs of planning a shooting. But no one noticed.” 
 
 The ad says, “Gun violence is preventable when you know the signs.” 
 
 “The PSA demonstrates how easy it is for one to overlook the signs of an at-risk individual demonstrating signs of violence, particularly gun violence, and that when one knows the signs, it can be prevented,” says a statement from Sandy Hook Promise. 
 
 The organization hopes the PSA will teach people how to recognize someone exhibiting at-risk behaviors and empower them to intervene. 
 
 Sandy Hook Promise states that 80 percent of school shooters and 70 percent of individuals who killed themselves told someone of their violent plans prior to taking action — yet nobody intervened. ||||| Nicole Hockley lost her youngest son, first-grader Dylan, in the December 2012 attack on the Sandy Hook Elementary School. Dylan was killed at age 6. 
 
 She wrote this open letter to Renae Hall, whose 6-year-old son Jacob was mortally wounded last week when a gun-toting teen opened fire at a school playground in Townville, S.C. 
 
 The text of her two-page missive: 
 
 I'm ashamed of myself. 
 
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 When I heard the news of the Townville Elementary school shooting, I was horrified. Too many similarities to the shooting at Sandy Hook School that took the life of my son, 19 of his classmates and six of his educators almost four years ago. A troubled young man (a child himself) with access to guns, killing one of his parents and then going to an elementary school and shooting first-graders and educators. 
 
 My first question was, “Are they OK?” Hearing that there were no deaths at the school eased my pain a little and I was able to return to my work. I knew the community would be traumatized. I knew families would be left wondering how this could have happened and what they could do to prevent it from happening elsewhere. I knew eventually we would hear about the signs and signals that the shooter gave off long before the violence occurred, but that were missed, not recognized, or not acted upon. I knew it was yet another preventable tragedy, but my immediate pain and fear was lessened because none of the children had been killed. 
 
 Until Saturday, when I learned of Jacob Hall's death. Seeing the picture his family released before he succumbed to his wounds killed me inside. Seeing his mother's face as she held her beautiful baby boy for the last time ... there are no words for the anguish I felt then and still feel today. 
 
 Nicole Hockley penned an open letter to Jacob Hill's mother. (Bryan Pace/for New York Daily News) 
 
 I also felt deeply ashamed. Ashamed that I had allowed a part of myself to accept the Townville Elementary shooting as another day in America, just because no one had died. For me to be complacent about gun violence, even for a moment, is unforgivable. I know the price of complacency and inaction. I know that until enough people are actively engaged in preventing firearm deaths and injuries, that change will not come. I don't just mean policy change — I mean change we can make in our own homes, schools and communities right now to identify and recognize at-risk behaviors and take action to intervene before a tragic culmination. The price of inaction is too high. The price is that people continue to die every day across our country, and communities continue to be traumatized. The price is the life of my six-year old son, Dylan. The price is the life of Renae's six-year old son, Jacob. 
 
 South Carolina first-grader dies days after school shooting 
 
 Renae — I am so sorry that I looked away, even for just a moment. Your son deserves so much more than that, as do you. 
 
 Although grief is very personal and unique, I have a sense of the journey you are on, the pain, and eventually hope, that walks alongside you. As I listened to you speak, I saw myself in you. The early shock and inability to understand what is happening, the feeling that the world is completely out of control and the ground you stand on is unstable. I heard you speak about Jacob and thought of the similarities with my Dylan. Both boys were born six weeks early. You had the joy of Jacob in your life for six years and four months, while I had my happiness with Dylan for six years and nine months. Jacob was your superhero; Dylan was my Superman. Jacob did not die alone; he died in your loving embrace. Dylan died in the arms of his special education assistant, who also died while trying to protect him. Both boys were exactly where they should have been when they were shot — at their school. I heard you say you believed Jacob was going to make a difference in the world. That is true, and I know Dylan's legacy is making a difference as well. 
 
 Renae Hall (l.), mother of Jacob Hall, talks to Starr Henderson during a wake service for her son. (POOL/REUTERS) 
 
 I am happy that you can find peace and forgiveness through your faith. I'm sad to say I have not found that yet — I am still mad at God. 
 
 I am also still angry with the politicians I've met over the last few years who were more interested in their careers than in making the smallest of policy changes that could save lives. I'm upset with the everyday citizens, just like you or me before we lost our boys, that remain uninformed or woefully misinformed on the issue of gun violence prevention, perhaps believing it will never touch them. And I am furious with the organizations and people that perpetuate the lies and profit from creating fear. 
 
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 But — as you said — there are good people in the world. I believe that, too. And I know that their numbers and hearts are stronger. Common sense and love will prevail, but sadly it will take time before we see significant violence prevention measures and firearm access improvements. Until that time, I am so sorry that more people will be injured or die, more communities will grieve, and more parents will feel the anguish over losing their child in a preventable tragedy. 
 
 Jacob Hall's superhero-themed funeral. (POOL/REUTERS) 
 
 My path in life since losing Dylan is to address any parent that feels helpless or hopeless on the issue of gun violence, and give them the tools to prevent these acts from occurring. Whenever I hear of another life saved or another tragedy averted, I am momentarily uplifted, but it will never be enough to fill Dylan's absence in my life. In time, I know you will find your own path and moments of happiness again, eventually even joy, but the absence of Jacob in your life leaves a hole no moments can ever fill. 
 
 As a mother and grieving parent, I am here for you now and always, in any way I am able. My heart is with you. My actions are dedicated to preventing more deaths and from more parents experiencing the loss of a child. I promise you, and all the other parents and grandparents receiving this message, I will never allow myself to be complacent for a moment again. ||||| The onset of this PSA from Sandy Hook Promise, an organization created in the wake of the Sandy Hook Elementary School mass shooting in Newtown, Connecticut, begins innocently enough. The video follows a boy, Evan (the same name as the video), exchanging messages on a desk in the school library with an unknown classmate. 
 
 The flirtatious messages are sent back and forth until the end of the school year, leaving a dissuaded Evan without a chance to learn the identity of his secret crush. However, in a last-ditch effort to learn who the person is, he exchanges yearbook signatures with classmates — one of which recognizes his handwriting from the desk. 
 
 While the two begin talking, however, an ominous figure emerges from the entrance of the building, taking out an assault rifle and cocks the gun as the screen fades to black. 
 
 "While you were watching Evan, another student was showing signs of planning a shooting," the corresponding text reads. "But no one noticed." 
 
 The PSA then relays the scenes of Evan at school, and in the background are several alarming signs of another student looking at gun videos on YouTube, being bullied by classmates, sharing photos with a gun on Instagram and reading a gun enthusiast magazine. 
 
 Giphy The warning signs 
 
 "It's important to know that one warning sign on its own does not mean a person is planning an act of violence," the Sandy Hook Promise website reads under the "Know the Signs" program. "But when many connected or cumulative signs are observed over a period of time, it could mean that the person is heading down a pathway towards violence or self-harm. By knowing the signs, you have the power to intervene and get help for that person. Your actions can save lives." 
 
 The organization was founded by several family members whose children were killed in the Sandy Hook Elementary School mass shooting in 2012. The nonprofit's goal is to protect children from gun violence. 
 
 Watch the powerful PSA from Sandy Hook Promise below: ||||| The mother of a 6-year-old who was killed in the Sandy Hook school shooting in 2012 wrote an open letter to the mother of Jacob Hall, the first-grader who died Saturday after he was shot at his South Carolina elementary school, saying she has yet to find peace and forgiveness after more than three years after the death of her son. 
 
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 Nicole Hockley -- who lost her youngest son, Dylan, after 20-year-old Adam Lanza opened fire on his first grade class at Sandy Hook -- wrote a letter to Renae Hall, which she provided to ABC News. 
 
 Hockley wrote she was "horrified" at the news of the shooting at Townville Elementary School and compared it to the mass shooting that took her son's life. 
 
 "My first question was, 'Are they OK?'" Hockley wrote, adding that her pain "eased" after she learned that there were no fatalities in the shooting. While it was another "preventable tragedy," she wrote, "immediately pain and fear was lessened because none of the children had been killed." 
 
 Drawing on her own experience, Hockley wrote that she "knew" the community would be traumatized and that "families would be left wondering how this could have happened and what they could do to prevent it from happening elsewhere. 
 
 Eventually, the details about the "signs and signals the shooter gave off, long before the violence occurred" will emerge, Hockley said. 
 
 When Hockley learned of Jacob's death, it "killed" her inside, she wrote, and she still feels that "anguish" today. Hockley said she feels "deeply ashamed" that she accepted the shooting in Townville as just "another day in America." 
 
 "For me to be complacent about gun violence, even for a moment, is unforgivable," the mother wrote. "I know that until enough people are actively engaged in preventing firearm deaths and injuries, that change will not come." 
 
 Hockley then detailed the similarities between Dylan and Jacob. They were both six weeks early when she were born and 6 years old when they died. 
 
 "Jacob was your superhero," Hockley wrote. "Dylan was my Superman." 
 
 Ken Ruinard/Reuters 
 
 A funeral fit for a superhero was held for Jacob on Wednesday, with pallbearers and mourners donning various costumes ranging from Batman, Superman, the Ninja Turtles and the Hulk. Jacob's own mother dressed up as Batman's sidekick, Robin, and the side of Jacob's casket was adorned with Ninja Turtles and lettering that read "Team Jacob." 
 
 After Jacob was pronounced dead on Saturday, his mother spoke to reporters, calling him an "angel" whose purpose on earth was to show love, kindness and forgiveness. Hall said Jacob is smiling down from heaven and that his memory is teaching her how to forgive. 
 
 Hockley did not share that sentiment, but said she was "happy" that Hall was able to find peace and forgiveness through her faith. 
 
 "I'm sad to say I have not found that yet -- I am still mad at God," she wrote, but added that she still believes "there are good people in the world." ||||| A mother who lost her 6-year-old son in the Sandy Hook Elementary School shooting has penned an open letter to the mother of Jacob Hall, the 6-year-old who died Saturday after being fatally wounded in September’s school shooting in South Carolina. 
 
 “As a mother and grieving parent, I am here for you now and always, in any way I am able. My heart is with you,” Nicole Hockley, whose son Dylan died in the Connecticut shooting, writes in the three-page letter. 
 
 Jacob was shot along with Townville teacher Meghan Hollingsworth and the second student, also 6 years old. Hollingsworth and the student were released from AnMed Health Medical Center the day after the shooting, a hospital spokesman previously told PEOPLE. 
 
 Jacob was shot in the leg and the bullet hit his femoral artery, causing massive blood loss leading to cardiopulmonary arrest, his family said. He was airlifted from the scene and remained on life support until his death. 
 
 The 14-year-old suspect is being charged as a juvenile in the shooting along with the death of his father, Jeffrey Osborne, who was found fatally shot near the school. 
 
 Hours after Jacob died, his mother, Renae Hall, spoke to reporters outside the hospital, calling Jacob a “superhero.” 
 
 “Jacob was forgiving,” Hall said. “What happened to Jacob, Jacob forgives already. He’s in heaven smiling down at us. He’s asking his mommy to be able to be strong to forgive just like he would have.” 
 
 Hockley tells Hall she has had a hard time coming to terms with losing her son, who was killed along with 19 other children in 2012. 
 
 “Jacob was your superhero; Dylan was my Superman. Jacob did not die alone; he died in your loving embrace. Dylan died in the arms of his special education assistant, who also died while trying to protect him,” Hockley writes. “Both boys were exactly where they should have been when they were shot — at their school.” 
 
 Seth Perlman/AP Seth Perlman/AP 
 
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 Hockley is the co-founder and managing director of Sandy Hook Promise, a nonprofit organization that provides programs and practices to help prevent gun violence. 
 
 “In time, I know you will find your own path and moments of happiness again, eventually even joy,” Hockley writes. “But the absence of Jacob in your life leaves a hole no moments can ever fill.” 
 
 “I am happy that you can find peace and forgiveness through your faith. I’m sad to say I have not found that yet — I am still mad at God,” Hockley writes. “As you said — there are good people in the world. I believe that, too. And I know that their numbers and hearts are stronger … [and] love will prevail.” 
 
 A GoFundMe page has been started to help Jacob Hall’s family with medical and funeral expenses.
– Meet Evan. He's a bored high school kid who starts defacing school property, er, doodling on a table in the library one day. Someone writes back. Messages are swapped as days pass, mystery and romance bloom. Evan wanders the halls, eyeing his classmates, wondering who his mystery penpal is, and as AdWeek puts it, "there ensues a back-and-forth that's pretty captivating. Perhaps too captivating." (To avoid spoilers, stop reading and watch the video.) The end result has been described as "jarring" (Kansas City Star), "chilling" (Mic), and "powerful" (People). While you and Evan are busy being captivated—especially as Evan meets his mystery penpal—one of Evan's classmates is lurking in the background providing warning signs that he's planning a shooting, which in fact interrupts that very meeting we've been waiting for. The ad comes courtesy of Sandy Hook Promise, run by family of the victims of the school shooting in Newtown, Conn. "When you don't know what to look for, or can't recognize what you are seeing, it can be easy to miss warning signs or dismiss them as unimportant," says Nicole Hockley, whose 6-year-old son, Dylan, died in the massacre. The organization, which says 80% of shooters tell someone what they're planning, aims to shine a light on the need to watch for those signs. (In Utah, a teen's own parents disarmed him inside a school.)