"Abandoned DNA", is it about an individual's privacy or about nailing the crook

"While secretly collecting a suspect's DNA may be an unorthodox approach to solving crimes, prosecutors say it crosses no legal boundaries - that when someone leaves their DNA in a public place via flakes of skin, strands of hair or saliva, for example, they give up any expectation of privacy"

[W]e can’t go anywhere without leaving a bread-crumb trail of identifying DNA matter.  If we have no legitimate expectation of privacy in such bodily material, what possible impediment can there be to having the government collect what we leave behind, extract its DNA signature and enhance CODIS to include everyone? 

—US Judge Alex Kozinski,

“When you’ve licked a stamp on your tax return you’ve sent the government a DNA sample.” 

Victor Weedn, Head of US Armed Forces DNA

Identification Lab

“Abandoned DNA” is any amount of human tissue capable of 

DNA analysis and separated from a targeted individual’s person inadvertently or involuntarily, but not by police coercion.

"Prosecutors tend to view abandoned DNA as akin to trash, which courts have upheld as fair game for investigators"

"Governments around the world are building up DNA databases to match suspects with evidence. The United States has the largest database, with over 5 million profiles. But Britain has the highest proportion of people catalogued, with its 4 million records equal to more than 6 percent of the population"

The brilliant method of collecting DNA samples from Anwar Ibrahim when he stayed overnight in a police lock up is now a subject of admissibility in a trial within a trial. Apparently in the US and the UK, abandoned DNA has been used to solve cases which were previously considered unsolvable:

Fingering `abandoned' DNA

BUFFALO, N.Y. — When a 60-year-old man spat on the sidewalk, his DNA became as public as if he had been advertising it across his chest.

Police officers secretly following Leon Chatt last August collected the saliva -- loaded with Chatt's unique genetic makeup -- to compare with DNA evidence from the scene of an old murder they believed he'd committed. Read in full here.

Though this method of collecting DNA had proved very useful to the Police in the US and the UK, critics there are more concerned about privacy. I am not versed in the Laws of Malaysia to comment on the legalities of "abandoned DNA" but one thing for sure is that the technology that we have in hand today is such that DNA extracted from the abandoned samples can be easily compared to existing DNA extracted from the scene of a crime.

Readers might find these articles interesting:

RECLAIMING “ABANDONED” DNA:  THE FOURTH 

AMENDMENT AND GENETIC PRIVACY by 

Elizabeth E. Joh

5 Facts (and Caveats) About DNA Profiling

I for one don't care too much about a person's privacy if the method can help nail a uncooperative criminal suspect who refuse to give his bodily sample for DNA testing.