Experts say such massive DNA sweeps can have a sobering social and legal price.
Besides eroding civil liberties and tearing neighbourhoods apart, a sweep known as a "blooding" can compromise the value of any DNA evidence it yields.
"The police think they are being very clever, but proceeding this way could very well jeopardize their case down the road," said Sanjeev Anand, a law professor at the University of Alberta.
Allison Dunfield and Kirk Makin, "Random DNA sampling questioned," The Globe and Mail, May 23, 2003
This case marked the first time that a murder was solved by the new procedure, developed by Dr. Alec Jeffreys at Leicester University in 1984. It allows investigators to read a individual's genetic code in a drop of blood or saliva or semen, and use that code to track down the criminal.
That's just what the police in Leicestershire did: Stymied, they tried this new procedure and ended up "blooding", the English term for taking blood samples, more than 4,500 males to find the killer.
Laurence Chollet, "The cop-turned-writer on the beat," The Record, February 21, 1989
The term was first used in 1987 by English police investigating two murders: the so-called "Narborough Village murders." These killings were the subject of Joseph Wambaugh's 1989 book The Blooding and (as the title suggests) he highlights the term throughout the book:
Joseph Wambaugh, The Blooding, William Morrow and Company, 1989
cord blood bank