Scientists have come up with a way to determine a person's age range based on blood. This can be very useful in crime scenes since it would be easier for investigators to determine if the blood belongs to a juvenile or an adult. Moreover, the method can determine the time when the blood was deposited at the scene.  

"It was recently shown that biomarkers present in blood can also identify characteristics of the originator, such as ethnicity and biological sex," reads the abstract of the study.  "A biocatalytic assay for on-site forensic investigations was developed to simultaneously identify the age range of the blood sample originator and the time since deposition (TSD) of the blood spot."  

The study, titled "Ages at a Crime Scene: Simultaneous Estimation of the Time since Deposition and Age of Its Originator" published on Analytical Chemistry in May, was conducted by scientists from the Department of Chemistry at the University at Albany, State University of New York. According to the National Geographic, they found a way determine a blood owner's age - a detail that current DNA analysis is not able to provide - by studying the levels of the enzyme alkaline phosphatase (ALP) in the blood.  

According to the report, ALP is released in adolescence during active development of the bones until around 18 years old for males and 17 years old for females. On the other hand, ALP levels decline in adults since bone development slows down.  

The team is continuing with the project, and they want to see if the age range can be narrowed down further to two to three years. They also want to see if various blood components are related to other characteristics.  

However, since the experiment was done in the laboratory under controlled conditions, it does not mimic the conditions in an actual crime scene. Forensic scientist George Schiro, the lab director at Scales Biological Laboratory, said that crime scenes are often found more than two days after the crime, and that the researchers used human serum, a chemical that's like human blood, but not real human blood. 

"There's more research that has to be done before it's going to be useful for any type of field investigation," he said, as quoted by NatGeo.   

He did say the project is good, and should it become possible to use in actual crime scenes, then, it would be helpful for the investigators to determine a culprit, particularly in combination with the other characteristics of a suspect.