One way to detect dark matter, if it exists, is to observe the decay products of dark matter annihilation, for example, when dark matter and anti-dark matter collide. There are definitely unidentified sources of cosmic rays including gamma rays which have been detected by astronomers coming from the center of the Milky Way galaxy.
Could these be dark matter?
A new study concludes that the answer is, probably not. The most likely sources are millisecond pulsars, although this isn't certain.
The study is: Samuel K. Lee, Mariangela Lisanti, Benjamin R. Safdi, Tracy R. Slatyer, and Wei Xue. "Evidence for unresolved gamma-ray point sources in the Inner Galaxy." Phys. Rev. Lett. (February 3, 2016).