The 12 students and one teacher killed in the Columbine High School shooting were remembered in a vigil on the eve of the 25th anniversary of the tragedy.

Fourteen mass shootings at U.S. schools since 1999's massacre at Columbine High School in Colorado have killed a total of 169 victims.

A Washington mother says she doesn't regret calling the police on her 17-year-old son, whose journal was allegedly filled with detailed plans about attacking his school on the anniversary of Columbine. "I know a lot of people that go to College Place High School," she said of her son's school. But her son's allegedly violent journal entries make her feel "like I've done something wrong," she said. RELATED STORIESBack-to-School PSA Spotlights Ordinary Items That Might Save Kids' Lives in a ShootingCan a Bulletproof Backpack Save Your Life in a School Shooting? Inside Edition Tests Them OutColumbine School Shooting Survivor Found Dead 20 Years After Massacre