Detective Shaun McCarthy has worked on a lot of cases in his more than 40 years with the Los Angeles County Sheriff’s Department. “I was 10 years as a street gang detective, and now I’m in my 23rd year as a homicide detective,” he said. “So, a total of 33 years as a detective.” These days, he devotes his time to the cases that remain unsolved. “To solve a homicide and prosecute somebody who committed the worst crime, there is nothing higher than that.” This is why he says he said couldn’t fully retire. McCarthy, like many others in the...