PARKLAND (Florida): U.S. Vice President Kamala Harris on Saturday remembered the victims of a 2018 mass shooting at the Florida high school where a gunman killed 17 people, pushing for states to strengthen laws on seizing firearms from high-risk people.

“We have a duty to remember and a duty to bear witness to what happened here,“ Harris said, referring to wounds both visible and unseen. “We must do better.”

After walking the halls of a Marjory Stoneman Douglas High School building in Parkland, where the murders happened and which is no longer in use, Harris spoke with 13 relatives of victims standing behind her, some holding photos.

As part of her visit, Harris called for 29 of the 50 states that have no “red flag” laws to pass them and encouraged 15 more states that have the laws to start using available federal funds to implement them.

The laws allow courts to issue “extreme risk protection orders” removing firearms from individuals considered at risk of harming themselves or others.

Six U.S. states both have such laws and are tapping $750 million available under the 2022 Bipartisan Safer Communities Act to implement crisis intervention programs.

Florida approved a red flag law after the 2018 shooting but has not used the federal funding, according to a White House official, who spoke on condition of anonymity.

The Parkland shooter, a former student there who was 19 at the time, had been seen for mental health issues. He pleaded guilty and was sentenced to life in prison.

The building where the shooting took place has remained largely unaltered since the 2018 shooting, with bloodstains and bullet holes still visible.

It looms eerily over the rest of the campus behind a chain-link fence, where it can be seen as current students walk to their classes, and serves as a constant reminder of the tragedy.

President Joe Biden has made gun violence a key issue in his 2024 reelection bid and tapped Harris, a former prosecutor, to oversee the effort. Both have traveled across the country to meet with people whose families died in mass shootings.

Some advocates regard the red flag laws as violating their constitutional right to bear arms, while gun safety advocates point to some studies showing the statutes can prevent some deaths. A new office announced by Harris, the National Extreme Risk Protection Order Resource Center, will work with states to implement the laws.

The United States has the highest level of firearm homicides among high-income countries with populations over 10 million, according to the Institute for Health Metrics and Evaluation at the University of Washington School of Medicine.

Biden, a Democrat, wants Congress to approve a new assault weapons ban and to require background checks for all U.S. gun sales. Each measure will be difficult to pass in a divided Congress. Republican candidate Donald Trump has previously supported red flag laws but opposed broader measures favored by Biden.