Who Dunnit? by Caleb and Hinerangi

In room 4, we have been investigating crime! Somebody was trying to steal something, and while they were leaving, they cut themselves while jumping through a window. We found some of their bloody clothing, and we started our work on the crime. Using CCTV footage, we narrowed it down to four people.  We still haven't found out what they stole, if anything, as there were so many priceless artefacts in the building. Then we started our detective work!

First off, we put some water on the bloody cloth. Then, we put that on the slide, and then put the slide under a microscope. On the first magnification (4x), we could see a pattern of red and a hairy substance. Then, when we tried the second (10x), we saw what we saw on the second scope, but bigger. On the third one (100x) we could see tiny blood cells. This confirmed that it was blood on the cloth.

Scientists at work

We then discovered that the blood was type A+. We also tested the victim, but found that their blood was O, so the blood definitely belonged to the criminal.

Putting anti RH into the blood to see if it will react

Next we took blood from our four suspects. We were looking to see which one of them was A+. To test the blood we put it in three punnets. In each punnet, we put three drops of anti-RH, anti-A and anti-B in three drops of the blood. If the blood reacted (agglutinated or got cloudy) we knew what it contained. For example, type A blood would react with anti-A.



Here are our results:

Suspect 1: AB + 
Suspect 2: B
Suspect 3: A+
Suspect 4: 0 -


Therefore, Suspect 3 is the robber!