This week, in public meetings and private conversations, Bostonians have been trying to process last Sunday’s shooting murders of three young women, all in their early 20s, and the wounding of a fourth. Reports have described the victims as strivers from good families and educational backgrounds whose friendship blossomed in one of the city’s better high schools.

The motive for these killings remains unclear. Police posited that one of the group had been targeted through gang involvement, prompting a gunman to open fire on all of the victims as they sat in a car on Harlem Street in Dorchester. But some law enforcement officials warn that the murders of Sharrice Perkins, Kristen Lartey, and Genevieve Philip could eventually be ascribed to other causes, even mistaken identity.

While the mystery surrounding these murders is both unusual and frightening, the proper response is both obvious and reassuring: Closer coordination between the police and community; efforts by community leaders to convince witnesses to come forward; and crackdowns on both drug-dealing and the distribution of illegal weapons.

Heinous cases like these invariably cause residents to question crime-fighting strategies. Frustration can fray the relationships between police and neighbors in high-crime areas. At a Wednesday public meeting, a few speakers tried to advance their own agendas, such as criticizing the police department for a failure to diversify its ranks at the upper levels. But nearly everyone else stayed focused on the immediate task — solving this crime and preventing others like it.

The fact that there has been relatively little “blame the system” talk reflects the hard work that has taken place over the years to build alliances among community groups, churches, the police, and City Hall. But much hard work remains to be done. Yesterday, the Boston branch of the NAACP called for a coordinated effort to address the availability of guns and drugs in urban neighborhoods and assess the effectiveness of the city’s violence-prevention programs.

No one should underestimate the insidious causes or effects of this crime.

No one should underestimate the insidious causes or effects of this crime. After attacks like this one, mothers and fathers across Boston are performing a basic calculation: Is the risk of a loved one getting caught up in such a gruesome incident worth the comfort and convenience of living near relatives, churches, and public transportation? People — and cities —live and die by such calculations.