CHICAGO — Mayor Rahm Emanuel’s first reading material each morning, at 5:30, is not a budget update, a legislative proposal or a packet of headlines. It is an e-mail from the Chicago Police Department listing the crimes that were committed during the night that just ended. By 7 a.m., he is calling Garry F. McCarthy, the police superintendent. That is unlikely to be their final conversation of the day, or even of the morning.

Mr. Emanuel listed safer streets among his top three priorities when he became mayor a year ago, but Chicago, the nation’s third-largest city, is now testing that promise. Homicides are up by 38 percent from a year ago, and shootings have increased as well, even as killings have held steady or dropped in New York, Los Angeles and some other cities. As of June 17, 240 people had been killed here this year, mostly in shootings, 66 more deaths than occurred in the same period in 2011.

“That’s somebody’s husband, somebody’s son, and they’re dying right on our block,” said Maya Hodari, who lives on a South Side street where two shootings have already taken place this year, one of them fatal and another as a toddler looked on. “It hurts.”