The father of one of the two students killed in the Annunciation Catholic School mass shooting urged parents to "give your kids an extra hug" as he remembered his son, Fletcher Merkel.

       "Yesterday, a coward decided to take our 8-year-old son, Fletcher, away from us," Jesse Merkel said during remarks outside the school on Thursday, publicly identifying his son as one of the victims killed in the "senseless act of violence" carried out by a 23-year-old former student at the school. "Because of their actions, we will never be allowed to hold him, talk to him, play with him, and watch him grow into the wonderful young man he was on the path to becoming."

       Jesse Merkel said his son loved his family, friends, fishing, cooking "and any sport that he was allowed to play."

       "While the hole in our hearts and lives will never be filled, I hope that in time, our family can find healing," the father said. "I pray that the other victim's family can find some semblance of the same."

       Fletcher and a 10-year-old were killed and 18 people -- including 15 kids -- were injured when the shooter opened fire through the windows of the Minneapolis school's church on Wednesday morning. All the injured victims are expected to survive, police said.

       Jesse Merkel praised the "heroic" response to the mass shooting.

       "Over the past day, I've heard many stories accounting the swift and heroic actions of children and adults alike, from inside the church," he said. "Without these people and their selfless actions, this could have been a tragedy of many magnitudes more for these people, I'm thankful."

       He asked that people give their children "an extra hug and kiss today" and that his son is remembered "for the person he was, and not the act that ended his life."

       The shooting occurred during a Mass that marked the first week of school, police said.

       The shooter -- identified as 23-year-old Robin Westman -- died at the scene from a self-inflicted gunshot wound, police said. Westman had attended the school, and Westman's mother previously worked in the parish, police said.

       A motive remains under investigation, and police said they've not identified a specific trigger for why the children at the church were targeted.

       Investigators determined that Westman "harbored a whole lot of hate towards a wide variety of people and groups of people," and also "had a deranged obsession with previous mass shooters," Minneapolis Police Chief Brian O'Hara told ABC News Live on Thursday.