The 30-second video shows a white man holding an assault rifle and a white woman holding a handgun.
Nearly 100,000 people have since viewed the same video, which comes after Mr Trump retweeted a video in which someone yells "white power" at protesters in a Florida. Both appear to point their weapons at participants in a racial justice protest walking by their home, with video the tweet Trump shared (via ABC News) showing the man involved yelling at the demonstrators.
St. Louis Circuit Attorney Kim Gardner is contemplating whether a pair of married lawyers broke any laws on Sunday when they aimed firearms at nonviolent protesters who were walking past the couple's Central West End mansion en route to a protest at the nearby house of Mayor Lyda Krewson.
In the video, a protester urges people to continue to walk past the couple and to not stop to argue.
Those calling for her resignation accused the mayor of intimidating protesters through "doxxing", the Internet-based practice of publishing someone's personal information as a vehicle for revenge via the violation of privacy.
Conservative observers suggested that the couple were using their Second Amendment rights to defend their home from "rioters" who invaded public property. Its exterior is made from limestone and marble, and its interior has been decorated to look like various Renaissance palaces from Europe, according to the profile. A sign on the gate says "private street".
The video was removed from Facebook and Krewson apologised on Friday, stating she did not "intend to cause distress".
One St. Louis alderwoman said the mayor had resorted to "intimidation of the residents [she was] elected to represent".