Complex sentence: The city recorded a total of 344 homicides in 2015, a number second only to the number recorded in 1993 when the population was 100,000 higher, and 2015 had the highest murder rate on a per capita basis ever recorded.
Split into simpler sentences: The city recorded a total of 344 homicides in 2015, a number second only to the number recorded in 1993 when the population was 100,000 higher. This was the highest murder rate on a per capita basis ever recorded.