In addition to the teenager, identified as Jose Quinonez, eight people have been shot within the past two weeks. Since January there have been five homicides and more than 50 assaults with firearms, Davis stated.
Most of the shootings are gang-related, and retaliation shootings are likely to occur unless police intervene, he added.
The crime emergency order, which took effect on May 21, more than doubles the number of patrol officers in the field, he said.
It allows the department to make swift assignment changes as needed. All regularly scheduled days off for each patrol team will be canceled on a rotational basis for the next 30 days.
"As a community we will not tolerate this level of violence. We are committed to action, and we will use all resources available to stem this violence and restore peace in our community," Davis said.
In a Twitter message to the community on May 19, Davis said last summer a combined program of social services and enforcement quelled violence between two feuding gangs, the Taliban and DaVill.
Davis said the city is now facing another spike of violence involving a different group. In the past five months gun violence has been perpetrated by the Norteno gang. A feud between the Norteno and Sureno gangs in 2011 resulted in the shooting death of 3-month-old Izack Garcia.
Last week the department announced it would continue its crime-fighting operations and will focus on the Nortenos, working closely with allied police agencies.
Police plan to host a summit of police chaplains and members of the faith community, increase re-entry services for parolees and increase summer Police Activities League (PAL) programming, including a graffiti-arts project for at-risk youth.
The department will work with the Ravenswood and Sequoia school districts to keep youth in schools and will increase the number of Fitness Improvement Training (FIT) Zones in the city to help residents feel safe on the streets through exercise-oriented activities led by police officers.