Police said that over the past 28 days, about 90 percent of shootings occurred on the street. That's up from about 65 percent.
They say the number of officers on the street could double or triple between 10 p.m. and 6 a.m. in 23 police precincts.
It's a response to an 11 percent increase in homicides over the last six months. Police say the homicide rate last year was the lowest since 1963.