South City Police Chief Mike Massoni joined about 200 other marchers. They walked to the site of a December 22 shooting that left three young men dead and three juveniles wounded.
Last week, the city council approved spending $400,000 to hire four new officers and launch other initiatives to improve conditions in old town.
"The city was rocked by these killings and we mourn along with the families and this neighborhood. We are embarking on what I believe is a long-term effort to create a safer neighborhood and improve the quality of life," Mayor Kevin Mullin said.
Organizers of the "Day of Healing" event are also pushing for a community center and mentoring programs for young people.