The number of homicides spiked 11.5 percent in Denver last year — the second year in a row the city saw an increase — even while overall rates for violent and property crimes held steady in 2016. The Denver Police Department reported a 1 percent increase in violent crime over 2015, which includes homicide, rape, robbery and aggravated assault, according to its year-end crime report obtained by The Denver Post through an open-records request. “The Denver Police Department commends our police officers for their hard work, especially during a time when Denver’s population is growing exponentially,” spokeswoman Christine Downs said in an e-mailed statement.