Police say a deputy U.S. marshal serving a felony arrest warrant was shot and killed Thursday evening outside a Tucson house on the north side. 

"This is a tragic night for law enforcement in Tucson and across the state of Arizona," Tucson Police Chief Chris Magnus told reporters late Thursday. "This is very tough."

Law enforcement agencies in Southern Arizona took to social media to share their condolences. 

More information: tucne.ws/12he