Following the fatal shooting of Minnesota Rep. Melissa Hortman and her husband, the president called Gov. Tim Walz "whacked out."

The children of Melissa Hortman and her husband Mark Hortman are speaking out on their parents' murders. “They were the bright lights at the center of our lives, and we can’t believe they are gone," Sophie and Colin Hortman wrote in a statement obtained by PEOPLE Monday.

The Hortman children are grieving following the Saturday killing of their parents, in what has been called a political assassination. Rep. Melissa Hortman was a longtime Democratic-Farmer-Labor legislator beloved around the Capitol even as she scored major legislative victories.

"The best way to honor our parents' memory is to do something, whether big or small, to make our community just a little better for someone else.”

Early Saturday morning, Minnesota House Speaker Emerita Melissa Hortman and her husband, Mark, were assassinated in their home.

Minneapolis mourns the assassination of Speaker Hortman and husband; city emphasizes democracy, safety, and community events.

U.S. Senator Amy Klobuchar tells PEOPLE about the legacy of her late friend Melissa Hortman, a longtime state legislator. Melissa and her husband, Mark Hortman, were fatally shot on Saturday, June 14,

Gov. Tim Walz called the event a “politically motivated assassination," with the attack marking the latest such incident over the last several years.