Mark Silano lived in a small town that rarely had serious problems. Recently, however, there had been a particularly brutal crime. A young girl had been found murdered in one of the town's parks. It had been almost three months and the police didn't seem to be getting anywhere.

As he was skimming his local newspaper, Mark came across an advertisement with a large black border. He read it carefully:

At first Mark didn't understand the implications of the ad. Then he remembered a show he had seen on television, which told about DNA fingerprinting and how criminals could be identified from tissue samples found at a crime scene. Mark was 22 and so fell into the category asked for in the ad. He thought he should volunteer, but he was really frightened of needles. He didn't want to give blood.

The first investigation to use DNA forensics took place in the United Kingdom in 1983. All the men in a town where a murder had occurred were asked to give blood samples for DNA testing. Colin Pitchfork, who was the murderer, tried to pay a number of people to give blood for him. When one man did, but then realized what this meant, Pitchfork was arrested.

DNA dragnets, as they are often called, are now used all over the United Kingdom, and are increasingly used in the United States.

1. What should Mark do?
2. What might happen if Mark does not volunteer?
3. Can authorities force Mark to give blood if he does not volunteer?
4. Why, do you think, does this technique work better in the United Kingdom than in the United States?
5. In one case, a baby was found abandoned. Police officials asked for DNA samples from all girls in the community who were between the ages of 12 and 18 and absent from school on the day of the birth. Do you see any problems with this procedure?
6. If an action is "voluntary," can one refuse to perform it? Why or why not?