Yes, you do. I haven’t met a homicide detective yet, that wasn’t a patrol officer first. And homicide doesn’t always take you right from patrol. Some officers do missing persons, narcotics, robbery, vice and similar divisions first. If you are eager to work homicide, be sure to state this out loud when you first start in patrol. Let the supervisor, or commander of homicide know this. If you do, you may not have to be in patrol, or another division, for very long. Do some reasearch before you apply at any police department. It’s of little value to you, to work for a police department, that has few homicides per year. At the risk of sounding morbid, or insensitive, you want to pick a department that has several per year. That gives you a better chance of becoming a homicide detective. You are doing your community a great service, if this is what you choose. My best wishes to you.