Actually this is not what happened, the suspect was tested because they found a partial match in the population, reached the dead father, reconstructed with the

Actually this is not what happened, the suspect was tested because they found a partial match in the population, reached the dead father, reconstructed with the help of people the possible mother, and then identified the son and tested it. Eventually since the phone was among the ones in the area, they would have reached him, but it was a totally different line of investigation that allowed to reach this specific person, so the fact the cell phone was attached to the tower was an acknowledge.