Simply Forensic · Case-based learning · Advanced

The Mixed STR Profile: Advanced Interpretation Challenge

Twelve case-based questions using a fictional STR electropherogram. Examine simulated peak-height evidence, evaluate uncertainty, and distinguish source from activity-level propositions. Includes complete explanations and an answer review.

Illustrative laboratory analyst examining a DNA profile; not a photograph of the simulated STR evidence
Context image from Simply Forensic’s media library. The plotted peak values below are fictional teaching examples.
Question 1 of 12Score: 0
Simulated electropherogram · examine the evidence

Illustrative training data, not a real STR profile. Simplified bars show labelled peak heights (RFU), not true electropherogram waveforms or sizing. Assume ordinary diploid genotypes and disregard known tri-allelic variants for the contributor-minimum question.

D8S1179

11650
121100
14390
16260

D21S11

29720
30900
32.2330

FGA

20115
211000
22600
24180

Illustrative analytical threshold: 100 RFU. For the one-repeat FGA 20/21 exercise only, assume a hypothetical 15% screening bound; this is not a recommended universal stutter threshold. Peak heights are fictional.

Accessible table: full simulated peak data
LocusAllelePeak height (RFU)
D8S117911650
D8S1179121100
D8S117914390
D8S117916260
D21S1129720
D21S1130900
D21S1132.2330
FGA20115
FGA211000
FGA22600
FGA24180

Loading the first question…

Challenge complete

Your quiz result

0%

Review all your answers

See the questions you answered correctly and incorrectly, your chosen answers, the correct answers and a scientific explanation for each.