President Obama announced Sunday that Osama Bin Laden has been killed in Pakistan Sunday by a CIA-led team. According to news reports, his identity was verified using facial recognition as well as DNA testing, which gave a 99.9% probability of a DNA match—meaning that it is virtually certain that the body in possession by the CIA is that of Bin Laden’s.
The DNA technology used to verify Bin Laden’s identity is the same one used in paternity testing. Basically, a biological sample is taken and tested using identifying genetic markers to create a unique DNA profile. The DNA profile is then matched to “known samples”—a reference DNA profile from either the person himself or his close relatives.
In Bin Laden’s case, it is reported that the CIA had reference samples from two relatives, including one of his sisters who had died in Boston. Siblings have a good probability of sharing inherited genetic markers, and depending on the markers they share, the probability of a match can be very high.
In a paternity test, DNA profiles of the father and child are compared to see whether the child has inherited the requisite number of markers from the father, therefore establishing a “match.”
 
Read more about the DNA test confirming Bin Laden’s death.
More from DNA discussions Popular Mechanics and NPR.