BALTIMORE — The pop-pop of gunfire echoed through the Druid Heights neighborhood several times on Saturday, but a volunteer cleanup crew barely reacted to the familiar sound. Instead, the volunteers noted what was missing: In the hours they spent clearing waist-high weeds and broken glass from a vacant lot, they saw no sign of the police.

They would have liked to have seen a patrol car roll by, but they were also well aware of recent reminders of the mistrust many Baltimore residents have of the police. In the last three weeks, videos became public that appeared to show officers planting drugs in two separate incidents, prosecutors were forced to drop dozens of cases that relied on the testimony of officers in those videos, and two detectives pleaded guilty to federal racketeering charges.

“People want the police to do their job and make the community safe, but then when the police show up, people are afraid of what they’re going to do,” said Darlene Cain, one of the volunteers and the president of a local advocacy group, Mothers on the Move. She knows those conflicted feelings better than most people; nine years ago, her son was killed in a confrontation with Baltimore officers.

Since Freddie Gray died in April 2015 from injuries sustained in police custody, this city has endured rioting, the failed prosecution of six officers charged in Mr. Gray’s death, a surge in violent crime and a jump in drug overdose deaths. A lacerating Justice Department report documented systematic racial bias and abuse by the Baltimore Police Department, drawing we-told-you-so’s from the city’s black majority.