A mitochondrial DNA (mtDNA) quantification PCR (qPCR) method was developed and applied in a study with experimentally degraded hair samples (first study) and in a criminal case (second study). In the first study, the amount of detectable mtDNA decreased drastically after an incubation time of 1 month on a moist tissue in a heating cabin at 37 degrees C. In the second study, when the qPCR assay showed positive quantification results, further analysis of 32 mtDNA single-nucleotide polymorphisms (SNPs) via SNaPshot technique was always possible, indicating that successful mtDNA SNP analysis of forensic samples can be guaranteed by pre-screening samples with the qPCR described here.