This isn't surprising considering that DNA fingerprint testing is not able to genetically differentiate between the good and evil twin. But now German-based company Eurofins MWG Operon says it has found a way to do just that.

Scientists from Eurofins, a genomic services company specializing in forensics and paternity testing, sequenced DNA from sperm samples provided by two identical twins and a blood sample of the child of one twin. They found five mutations, known as Single Nucleotide Polymorphisms (SNPs), in the child and the father, but not in the twin uncle. This finding was confirmed using Sanger sequencing.