‘Touch DNA’: Police Use Advances in Genetic Science to Solve Crimes


DNA. It can be used to identify suspects, make connections between crime scenes – or exonerate those wrongly convicted of crimes. It’s an increasingly powerful crime-solving tool that has also fueled civil liberties and privacy concerns.

DNA is relatively new – barely in your 30s. But as a science, it has progressed rapidly. Authorities last month touted how “tactile” DNA technology quickly identified an alleged serial rapist, James W. Daniel III, based on a few skin cells left in his jeans pocket. ‘a woman who reported an attack.

Touch DNA is nothing new. But analysts at the Cuyahoga County Regional Forensic Science Laboratory say they are increasingly able to obtain DNA profiles with smaller samples – just a few cells – and faster than ever. previously. In an emergency, they can get a profile within 24 hours. The office trains police using mock crime scenes to better identify evidence that may contain the correct DNA to help identify a suspect. Here’s a quick look at the DNA techniques being used locally at the Cuyahoga County Regional Forensic Science Laboratory – and what could happen.

Tactile DNA

We are constantly shedding skin cells and leaving little traces of ourselves behind that show where we’ve been and what we’ve touched. Scientists can take swabs, cuttings, or lift cells with duct tape to get a DNA profile. This technique is different from testing bodily fluids, such as saliva, blood, or semen. Fluids generally contain more genetic material and are easier to test.

Police secure a crime scene and begin to determine where to take samples. Obviously, there will be considerable amounts of DNA from the occupants. They will search for the genetic material of other people who may have been present when the crime was committed.

DNA “low copy”

This term refers to a reliable DNA profile obtained from very small pieces of DNA, be it fluids or skin cells.

Mitochondrial DNA

Most DNA profiles are developed from a sample taken from the nucleus of a cell. However, some DNA is located outside the nucleus and can be used to obtain a profile. Also called mtDNA, this type is almost exclusively made up of genetic material passed down from your mother.


Family DNA research

This is a controversial method of expanding the DNA search network not only to find a person who left DNA at a crime scene, but also to find them among loved ones who may have DNA. similar. The method is still legally questionable and is not yet in use in Ohio. A new DNA comparison is performed once a suspect is identified, but some fear this could lead to “guilt by genetic association” as many comparison samples in state and national databases are taken from accused felons or condemned. Because it is based on a comparison of the “Y” chromosome found in men, it cannot be used to identify a woman.

Fast DNA

The latest advancement in DNA is essentially speeding up the process of obtaining a DNA profile from evidence or from a person. Machines, the size of an office copier, can be used to analyze swabs taken from suspects – or objects such as a cigarette butt. And they can do it in under two hours. Proponents argue that a quick turnaround could make it easier to investigate violent criminals and lead to quick arrests. Critics fear the machines and results will be misused by local law enforcement agencies who lack the high standards accredited crime labs do. Currently, the profiles identified by the machines cannot be entered in the national CODIS databases. Machines are tested in some small Pennsylvania police departments. In 2012, the Palm Bay Police Department used a rapid DNA sample to obtain a profile used to troubleshoot a burglary.

Rachel Dissell and Chris Morris | The simple merchant

Leave A Reply

Your email address will not be published.