ST. LOUIS – The Missouri History Museum has spent two years collecting artifacts from the unrest in Ferguson, but there's a conspicuous absence of items provided by Ferguson City Hall.

The museum has artwork from boarded-up windows, protesters' gas masks, empty tear gas grenades and even clothing worn by protesters in the weeks following Michael Brown's shooting death by a police officer. But Ferguson officials have yet to contribute anything to the collection.

City Hall spokesman Jeff Small said that the city isn't involved because it hasn't been formally asked to participate, and, moreover, it has nothing to offer. "At no point did the city ever maintain any collection of items," Small said.

Mayor James Knowles said he would help, but hasn't personally been contacted by the museum about the collection since the end of 2014.

Activists and museum researchers say they'd be surprised if the city has nothing of historical significance.

Museum director of collections Chris Gordon said that the city "might not understand some of this material may be of interest to us."

The museum is also recording oral histories of the events in Ferguson from people who lived through them. Gordon said that about 10 such interviews have been recorded.

Emily Davis, a Ferguson activist who contributed artwork to the collecting initiative, said it's difficult to believe City Hall isn't in possession of items that might be considered artifacts. Davis said she thinks the city simply doesn't want to remember the events between Aug. 9, 2014 — when Brown, an unarmed black teenager, was shot — and November 2014, when a grand jury declined to indict police officer Darren Wilson in the killing.

"They want to pretend this didn't happen," Davis said.

Small said it's not city officials' role to act as historians, but that they are supportive of efforts to preserve the history for research and education. He added that there are concerns about how the events might be portrayed and said that some groups might want to exploit events for their own agenda.

"We understand those who would have a purpose of doing something that is meaningful that acknowledges the controversial nature of the events, but that presents any materials in a respectful way," Small said. "No one wants to see anything exploited in some manner or used for some type of ill will."

Small said that the city would consider a "formal request" to participate, but didn't elaborate. Knowles said he would only need to be personally contacted.

At one point, the Missouri History Museum and the city of Ferguson were progressing on a formal collecting agreement, Gordon said. But those talks were tabled in the spring of 2015 following a Department of Justice report excoriating city management, and an exodus of the city's top brass, including resignations by the police chief and city manager.

"At that point a whole new group of people came on and it's been our goal to reach out and re-establish a new relationship with the new people," Gordon said.

Knowles said that City Hall has been short-staffed in addition to the administrative turnover. Preoccupation with implementing a consent decree with the Department of Justice and providing basic services take precedent over collecting artifacts for the history museum, he said.

Knowles said the city has helped the Ferguson Historical Society collect artwork from boarded up windows.

"We'd be happy to provide what we can, but some requests we just can't fulfill because we don't have those items," Knowles said.

Specifically, the Missouri History Museum had requested Wilson's uniform, badge and firearm. Knowles said the uniform and badge are Wilson's personal property, and the firearm was handed over to St. Louis County as evidence when the case was being investigated.