Earlier quoted context omitted.
Just because the government finds your DNA at the crime scene doesn't mean they know it's yours. They have to match it against some sort of database that connects the DNA to your identity.
With enough corruption, they might also "find" it on the crime scene.
Consider a public bathroom: how much DNA is at that location? How much is relevant to the event?
Consider a corrupt lab tech: The DNA at the event might be reported as DNA from their database. Does a defense attorney get to see the untainted sample?
Consider a corrupt/hacked DNA database: The database might report that the DNA belongs to one individual when it actually doesn't. Does a defense attorney even get to see the source code?
In these scenarios, the link to any individual is either of little consequence, or fraudulent.