Earlier this spring, a teenager was gunned down at a St. Paul park where dozens were gathered for a cookout. In Minneapolis, a 59-year-old grandmother was shot and killed, caught in a crossfire while driving with her grandchild. And a 10-year-old girl was injured while watching TV inside her north Minneapolis home when stray shots pierced a wall.

In response to such gun violence, good people gather in both cities, often with police officers, to march, hold vigils, and denounce senseless deaths and injuries. It’s become almost routine for city officials and communities to come together and say they “won’t tolerate’’ the continuing bloodshed.

Yet to really make a difference, affected communities must heed the pleas of the mourning moms, MAD DADS and Mother’s Day marchers. Speak up, and share what you’ve seen to help convict those who terrorize neighborhoods with firearms.

That can understandably be challenging for some communities. Gang and other criminal retribution can frighten people into silence. In addition, Black Lives Matter has focused a legitimate spotlight on police misconduct against African-Americans. Years of bad relationships and mistrust can make witnesses and victims reluctant to go to police with information.

Still, law-abiding citizens must work to rebuild that trust to reclaim neighborhoods. Gun violence in the Twin Cities has been a major concern in 2016; the number of people shot in Minneapolis is outpacing last year’s figure. And in St. Paul, a spate of spring shootings prompted officials to plead for residents to put down their guns.

According to Minneapolis Police Department calculations, 131 people have been wounded or killed by gunshots in the city so far this year — 80 percent of them on the North Side.

Sending a strong message that neighbors are watching and that shooters will be caught, convicted and punished will help curb the killing. Longer-term work must continue on youth violence prevention, including programs that focus on improved education, mentoring, jobs and other constructive activities. And elected officials must push for reasonable gun regulations — such as more comprehensive background checks — to reduce easy access to firearms.