The Saturday night shooting was not the first time protesters were injured in the city.
Police said on Saturday homicide detectives were investigating the shooting. That person was hospitalized with non-life-threatening injuries.
Almost four months after the fatal police shooting of Breonna Taylor, the Louisville Metro Council announced it will launch an investigation into how the incident was handled by Louisville Mayor Greg Fischer's administration.
The protest followed an incident at a tent encampment in Jefferson Square Park, where gunfire erupted Saturday; a protester had opened fire, wreaking chaos among campers who also were armed.
The shooting was at least the second during almost a month of protests in Louisville over Taylor's death.
People were then seen cowering for cover, with the man filming the horror gasping "oh my God!" as he came across someone laying in a pool of blood in Jefferson Square Park following the 9 p.m. shooting. For almost a month, protesters have been calling for the officers involved in her death to be charged. One of the three officers involved in her shooting was sacked last week.
Lopez had previously attended protests at the park and been arrested twice before on rioting related charges, according to Louisville police. Police returned fire, hitting Taylor eight times, resulting in her death.
A protester speaks with Louisville police officers who were handing out flyers on an overnight camping ban. The police were executing a so-called no-knock warrant, which allows them to enter without identifying themselves. "This is absolutely not what they wanted or any of us wanted", Mr Fischer said. Things changed last night when shots rang out in the park, leaving one dead and one other shot.
Chuck Gerth said his wife warned their son about going to downtown Louisville on Saturday "because she thought it would be unsafe, but he said, 'No, I feel the need to go down and support the injustices and what's going on'".
It was unclear if there was more than one shooter and authorities have yet to release any details of the victims.
The protestors were demanding justice for Breonna Taylor, a 26-year-old African American emergency medical technician who was killed by the Louisville Police as they stormed into her apartment in plain clothes with a no-knock search warrant.
"The citizens of this community, including members of this Metro Council, have been very upset with the perceived lack of transparency by the city", said Brent Ackerson, who chairs the Louisville Metro Council's government oversight committee.