Nationwide protests after the deaths of two unarmed black men by police in Missouri and New York might cause officers to hesitate to use deadly force for fear of becoming the "next Darren Wilson," Baltimore's mayor said Wednesday.

Meanwhile, police unions say departments across the country are battling anxiety that could compromise officers' safety. They called upon more police chiefs and elected leaders to vocally back officers, who have felt their public support erode even as they continue to do dangerous jobs protecting communities.

On Sunday, Baltimore police officer Andrew Groman was shot in the abdomen after a traffic stop in West Baltimore, where police say he pulled out his Taser when a passenger refused to get out of a car. As Groman fired the stun gun, police say, 19-year-old Donte Jones pulled out a concealed .357-caliber handgun and fired three times. Several officers surrounded the car but none returned fire, police said.

During a weekly news briefing Wednesday, Mayor Stephanie Rawlings-Blake said intense public scrutiny and four months of protests against police brutality in Baltimore may be affecting officers' ability to act at critical moments, the Baltimore Sun reports.