DES MOINES, Iowa (AP) — Police data shows that Des Moines saw the highest number of homicides in nearly 40 years in 2017. The 25 homicides last year in Iowa’s largest city is the greatest amount since 1978, when 27 people were killed. The Des Moines Register reports that law enforcement officials attribute many of the homicides to soured personal relationships, gang-related violence and a trend of young adults solving conflicts and social media disputes with guns.

Police Chief Dana Wingert says conflict resolution has gone to the extreme. The city’s police department had a 72 percent homicide clearance rate in 2017, up from 57 percent in 2016. No individual has been arrested or identified as responsible in seven of the 25 killings. A clearance doesn’t mean a suspect has been prosecuted.