Can someone else transfer my DNA?

Yes.

Another person can transfer your DNA to an item or location without you directly touching it.

DNA can move through multiple pathways. While direct transfer occurs when a person physically touches an item or another individual, transfer can also occur indirectly through intermediary people, objects, clothing, or shared environments. Any transfer that does not occur through direct contact is termed indirect transfer.

Indirect transfer is not limited to a single step. DNA may be passed from one person to another and then to an item (secondary transfer), and from there to further individuals or surfaces (tertiary, quaternary, and beyond). With each stage, the pathway becomes more complex, but transfer remains scientifically possible.

Research has demonstrated that everyday activities — handling objects, sharing spaces, contact with clothing, or interaction between multiple individuals — can result in DNA being moved across several steps without the original person ever contacting the final surface.

Laboratory testing can detect DNA and sometimes identify a contributor, but it cannot determine the pathway by which the DNA arrived. It cannot distinguish between direct contact and multiple stages of indirect transfer.