A union representing US Centers for Disease Control employees has demanded that the federal government condemn vaccine misinformation after a man who evidently blamed the Covid-19 vaccination for making him depressed and suicidal aimed gunfire Friday at the CDC’s headquarters in Atlanta.

The 30-year-old shooting suspect, who killed a police officer and died during the attack, had also tried to get into the CDC’s headquarters – but he was stopped by guards before driving to a pharmacy across the street and opening fire, a law enforcement official told the Associated Press on Saturday.

The CDC workers’ union said the deadly violence on Friday was not random and “compounds months of mistreatment, neglect, and vilification that CDC staff have endured”. It said vaccine misinformation had put scientists at risk.

The American Federation of Government Employees, Local 2883, added that the CDC and leadership of the Department of Health and Human Services (DHH) – headed by Trump administration appointee and avowed vaccine safety skeptic Robert F Kennedy Jr – must provide a “clear and unequivocal stance in condemning vaccine disinformation”.

Such a public statement by federal officials is needed to help prevent violence against scientists, the union said in a news release.

“Their leadership is critical in reinforcing public trust and ensuring that accurate, science-based information prevails,” the union said.

Patrick Joseph White was armed with five guns, including at least one long gun, when he attacked, said an official who spoke to the Associated Press on condition of anonymity because they were not authorized to publicly discuss the investigation.

White’s gunfire hit at least four CDC buildings, agency director Susan Monarez said on X.

DeKalb county police officer David Rose was mortally wounded while responding. Rose, 33, a former US marine who served in Afghanistan, had graduated from the police academy in March.

White was found on the second floor of a building across the street from the CDC campus and died at the scene, Atlanta police chief Darin Schierbaum said. He added that “we do not know at this time whether that was from officers or if it was self-inflicted”.

The Georgia bureau of investigations said the crime scene was “complex”. The agency added that the investigation into the violence would take “an extended period of time”.

Fired But Fighting, a group of laid-off CDC employees, has said Kennedy Jr is directly responsible for the villainization of the CDC’s workforce through “his continuous lies about science and vaccine safety, which have fueled a climate of hostility and mistrust”.

Kennedy Jr reached out to staff on Saturday. The DHH secretary said “no one should face violence while working to protect the health of others”.

Dr Jerome Adams, who served as the US surgeon general during Donald Trump’s first presidency, said Kennedy’s response to Friday’s shooting was “tepid”, late and amounted to a “failed … test” of his leadership.

“That’s not even considering how his inflammatory rhetoric in the past has actually contributed to a lot of what’s been going on,” Adams said on Sunday on CBS’s Face the Nation.

Adams said the mRNA-based vaccine technology that helped end the Covid-19 pandemic saved more than 2 million lives “by the most conservative estimates”. His comments came days after Kennedy moved to cancel $500m in mRNA vaccine research.

Thousands of people who work on critical disease research are employed on the attacked campus. The union said some staff were huddled in various buildings until late at night. More than 90 young children were locked down inside the CDC’s Clifton school.

The union said CDC staff should not be required to immediately return to work after experiencing such a traumatic event. In its statement on Saturday, it said windows and buildings should first be fixed and made “completely secure”.

“Staff should not be required to work next to bullet holes,” the union said. “Forcing a return under these conditions risks re-traumatizing staff by exposing them to the reminders of the horrific shooting they endured.”

The union also called for “perimeter security on all campuses” until the investigation is fully completed and shared with staff.

White’s father contacted police and identified his son as the possible shooter. He said White had been upset over the death of his dog and also had become fixated on the Covid-19 vaccine, according to the law enforcement official who spoke to the AP anonymously.

A neighbor of White told the Atlanta Journal-Constitution that White “seemed like a good guy” but spoke with her multiple times about distrusting Covid-19 vaccines in unrelated conversations.

“He was very unsettled, and he very deeply believed that vaccines hurt him and were hurting other people,” Nancy Hoalst told the Atlanta newspaper. “He emphatically believed that.”

But Hoalst said she never believed White would be violent: “I had no idea he thought he would take it out on the CDC.”