Get Your Message Across
To get your message across and avoid shouting over everyone, pick the largest, loudest, or recognized leader of the throng and ask him or her to go off to the side and speak to you, one-on-one. If you believe that the person is on your side, empower him or her to act as your agent in communicating the need for scene integrity.
If push comes to shove - and sometimes it does - you may end up having to use force, even arrest a loved one.
One night a distraught father showed up at the scene of his son's murder and punched a deputy who'd prevented him from accessing the crime scene. Some force was effected and the man was arrested. Fortunately, neither the deputy nor the father was injured, and no criminal charges were brought against the father, who with the advantage of a day's reflection realized that we were acting on behalf of him, his son, and their family.
I'm not saying that we're meant to be punching bags, or to put up with other aggravations. But there are times when it's "no harm, no foul," and one should consider the spirit of the law in deciding what to do about distraught loved ones.
It Takes All Kinds
Remember, looky lous include our own. Cops are equally capable of tracking contaminants into a crime scene as they are kicking evidence out.
You never know who might show up at a crime scene.
Journalists are a given. Local political types have proven nosey enough. It's been said that Jesse Jackson never saw a camera he didn't like, and from coast to coast, community controverts such as Al Sharpton or Earl Ofari Hutchinson may make an appearance to get some air time and chastise cops for not having prevented the tragedy (the following week, they'll be decrying the same cops for racial profiling).
Wives, ex-wives, and girlfriends have shown up at crime scenes at the same time, sparking girls gone wild free-for-alls.
Larger agencies may find weekend duty commanders and others wanting a look inside. Unless it's pertinent to homicide's investigation to allow them in, keep 'em out. That, or ask them if they want to assume control of your investigation.
Then there's the suspects themselves. Sometimes they'll insinuate themselves among the looky lous to see what's going on, and how the investigation is going. Keep an eye out for suspicious types.
Graham County Sheriff Don Scott obtained the name of serial killer Francis Donald Nemecheck after he'd shown up at a crime scene. His follow-up resulted in Nemecheck's arrest and conviction for multiple murders.
One last piece of advice: Watch what you say. Even if no journalists are around, what you say can be communicated to them from some looky lou who overheard some speculative conclusion that can come back and bite you later.
Crime scenes are inherently stressful, and can be aggravated by countless others. But by having a game plan in place ahead of time, you can help prevent it from becoming more so.