Paternity Testing for Deceased Alleged Father.
This test is performed when the alleged father is deceased.  In many cases, the Medical Examiner's Office can provide a blood or tissue sample. 
A blood stain or blood spot card from the Medical Examiner's office is an ideal sample.  You can also determine if a vial of blood is available in newer cases (30 days or so).  With this sample from the deceased alleged father, the paternity of the child can be determined. 
Testing requires samples from the mother, the child, and the blood or tissue sample from the deceased alleged father.  The tissue sample cannot have been preserved in formaldehyde or paraffin wax. 
Average turnaround time is approximately 2 weeks; however, this can vary depending on the type of sample provided for the alleged sample.