WASHINGTON (AP) — Four years after 17 people were gunned down at Stoneman Douglas High School in Parkland, Florida, families and gun control advocates are pressing President Joe Biden to do more to address gun violence.

One father of a victim killed in the shooting sent an early morning tweet Monday, the anniversary of the Parkland shooting, saying that he’d climbed a 150-foot-tall crane near the White House.

“The whole world will listen to Joaquin today. He has a very important message,” the father, Manuel Oliver, said in a video tweeted at about 6:50 a.m., referring to his son, Joaquin Oliver. “I asked for a meeting with Joe Biden a month ago, never got that meeting.”

Oliver unfurled a sign that showed a photo of his son and criticized Biden for gun deaths on his watch. Police were called to the scene, where at least two people were on the crane. They said later that three people were taken into custody but didn’t identify them.

Meanwhile, dozens of advocates were set to rally outside the White House and unveil a website chronicling the 47,000 gun deaths and 42,000 gun injuries in the country since Biden was inaugurated. The tracker also lists the number of young people killed and injured as well as the number of mass shootings in the same time frame, and it includes a feature allowing users to publicly call on Biden and other administration officials to act against gun violence.

“As a candidate, Joe Biden promised to prioritize gun violence prevention. As president, Joe Biden has not,” said Igor Volsky, founder and executive director of the group Guns Down America.

In his first year in office, Biden’s efforts to pass legislation to tighten gun laws haven’t left the drawing board. He also was forced to pull his nominee to lead the Bureau of Alcohol, Tobacco, Firearms and Explosives. The group is calling on Biden to stand up a national office to address gun violence and to make a new nomination to head the ATF.

Biden said in a statement before the planned protest that the movement to end gun violence is “extraordinary.”

“We can never bring back those we’ve lost. But we can come together to fulfill the first responsibility of our government and our democracy: to keep each other safe,” he said. “For Parkland, for all those we’ve lost, and for all those left behind, it is time to uphold that solemn obligation.”

Since the Parkland shooting left 14 students and three staff members dead, gun violence at schools has only risen. There were at least 136 instances of gunfire on school grounds between Aug. 1 and Dec. 31, according to a tally last week by the gun control advocacy group Everytown for Gun Safety.

Biden has acted to crack down on “ ghost guns,” homemade firearms that lack serial numbers used to trace them and that are often purchased without a background check. He has worked to tighten regulations on pistol-stabilizing braces like the one used in a Boulder, Colorado, shooting that left 10 people dead. He’s also encouraged cities to use their COVID-19 relief dollars to help manage gun violence. But these efforts fall far short of major change.

There are limits to what the president can do when there is no appetite in Congress to pass gun legislation. The strongest effort in recent years failed, even after 20 children and six adults were killed in the 2012 Sandy Hook school shooting in Newtown, Connecticut. Parkland happened six years later.

Biden, a Democrat, said he’s asked members of Congress to provide funding to help reduce violent crime and said they must pass legislation requiring background checks on all gun sales, banning assault weapons and high-capacity magazines and eliminating immunity for gun manufacturers.

The U.S. Secret Service’s National Threat Assessment Center studied school attacks nationwide from 2006-18 and reported that most attackers were bullied and that warning signs were there. Most important, the researchers said, about 94% talked about their attacks and what they intended to do in some way, whether orally or electronically, and 75% were detected because they talked about their plots. About 36% were thwarted within two days of their intended attacks.