In my hands, the "unknowns" become known

At HSA’s Forensic Chemistry & Physics Lab, you may hear Kang Hua or her colleagues often say "we need to run’".

Don’t get the wrong idea, they are not a bunch of exercise fanatics. Rather, they need to "run" a sample or "run" an instrument. The lab is a place she really enjoys being at and while she finds herself reviewing reports more frequently in the office now, she will always make time for her "runs" in the lab.

1. You specialise in examining trace evidence, in particular chemical analysis of unknown substances. Can you tell us more?

Some common types of trace evidence are paint, fibre and glass, and any substances of unknown sources can be termed as ‘unknowns’, whether they are solids, liquids or gases.

The cases I work on are often unique as the samples submitted are of a wide variety. This means I need to apply different analytical methods to tackle each case and may sometimes even need to look up specific journal articles to understand more.  

I enjoy chemistry and I like being in the lab, “running”, and analysing things. Science is interesting to me as I learn a lot of new things all the time. Furthermore, in my work where I come across various types of unknown substances, I get to learn and find out what these substances are. My work also exposes me to learning how to “run” a wide range of instruments.

2. What kind of samples do you work with?

The samples we receive can come in any form and the general request would be for us to help determine what is the sample or what is in the sample.

Some of the cases include suspected adulteration in food and beverages (e.g. with cleaning agents) and unknown substances used in acts of mischief.

The police may come to us with requests to analyse food or beverages suspected to have been tampered with. For example, a person may have reported that he/she had consumed some food or beverage and fell sick; or that there’s a weird smell, taste or appearance, and we will then be asked to determine if something was added to the food or beverage. Some of the food items I’ve analysed include bird’s nest soup, milk and Milo.

We find that food exhibits are one of the more challenging type of exhibits since they are prone to spoilage and add another dimension to our analysis. We will have to process such cases very quickly.  There are also a lot of components in food, such as oil and proteins, which may obscure the targeted compounds we are looking out for.

There was one challenging case where I was given a bottle to analyse the liquid inside but it looked empty. In order to analyse the remaining droplets of liquid inside, I needed to use a pipette to draw out every single precious drop.

3. Can you tell me about an interesting case you have worked on?

I had this case where someone visited a casino and marked the cards with some powdery substances. We had to determine the substances used to mark the cards. After marking the cards, he also touched his hands on his pants. So we also had to associate the substances found on his pants to the residue found on the cards.

This was quite an interesting case as in my personal experience, it was the first of its kind that I had to handle, in terms of the case background and the types of exhibits submitted. The markings were not that obvious and we had to use a forensic light source to shine on each of the cards in the decks submitted, not all of which were marked, and that helped to make the markings more apparent to the naked eye.

4. What is a common misconception people have about your job?

People tend to think we can process things very quickly. From watching TV shows, they may think that an entire case can be solved within a day. Some TV shows depict forensics as magic. I remember watching one episode where they were able to specify the petrol station from which the petrol came from. However, it’s actually not that simple, as the same source of petrol may be distributed to many different petrol stations and it’s not easy to trace it to a particular petrol station.

5. What keeps you going every day?

I find meaning in my job and what I do is important to support the administration of justice. Work is challenging but we enjoy the satisfaction at the end of the day when we succeed in analysing the unknown substance to provide investigative leads to the police.

6. What career advice would you give to students who want to pick up a career in forensic science?

Don’t be influenced by the forensic shows you see on TV as they are often unrealistic, over-glamourised and yet at the same time, over-simplify the work of forensics. Firstly, you need to be interested in science. You also need to study science and be good in it. You must be prepared to spend long hours in the laboratory and if working with trace evidence, sitting still at a laboratory bench looking for tiny objects under the microscope. 

7. Where do you see the future of forensics in your area of specialty?

With greater accessibility to information from the Internet, we anticipate that crimes will become smarter. Often, we discuss among ourselves what would be the perfect crime. To us, knowing the limitations of science, a perfect crime is simply one that is able to work around the loopholes, making it difficult to trace back to the perpetrator.

With that in mind, as forensic scientists, it is imperative that we stay ahead in terms of our knowledge and technology so that we are always one step ahead. This means equipping the laboratory with the latest library databases, as well as the latest technological developments.

The technology may include instruments of greater sensitivity, techniques that are more robust and can handle sample matrices which are more complex, as well as software add-ons to existing analytical techniques. Various chemometric tools have been developed to handle the interpretation of large volumes of data to recognise patterns, group the data into clusters and form complex associations and links between them. It is exciting that with digital transformation, we will be able to cut down on manual tasks and process information faster through automation.

In the future of forensics, it will not be far-fetched to one day see artificial intelligence working alongside forensic scientists in laboratories as partners in fighting crime.

 

 

 

 

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