Ljubica Lazarevic
Aug 17 · 3 min read
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*Now updated with hints and solutions!*

Summer of Nodes: Week 3 — Whodunit — Murder Mystery

Hello everybody!

Summer of Nodes 2020 is now over. If you’ve not had a chance to look at the challenges, you can always have a go at your leisure:

This week’s theme — whodunit?

Another popular activity we like to do during our days off are things that make us think, solving problems, and the like. Board games, murder mysteries are popular as well.

This week’s Summer of Nodes challenge is going to take the excellent Knight Lab’s “The SQL Murder Mystery”, with a graph spin, based on the data from their repository. We are going to be doing some sleuthing based on that data to figure out who the suspect is.

These challenges should take approximately an hour each, depending on experience.

Don’t forget, on Thursday we’ll be providing some hints and tips, just in case you need them.

Beginner’s challenge — find the suspects


We would like you to use your sleuthing skills along with your graph prowess to figure out who the suspects are! You may use Neo4j Browser and/or Neo4j Bloom to solve this mystery, whatever works best for you.

Beginners challenge:

Find out the suspect and their accomplice.

You will be:

  • Loading the data based on this script
  • You’ll want to start with reading the crime scene report from Jan 15th, 2018 that took place in Graphville
  • Tell us who committed the crime and who else was involved!

You will probably find a copy of the data model helpful for your enquiries

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Some helpful resources

  • If you’ve not already done so, and are completely new to Cypher, you can learn more in the developer guide
  • You can get the specific on Cypher syntax here
  • The Cypher reference card may also prove useful

I am completely new to Neo4j, and Sandbox, and I don’t know how to get started. Help!

Here’s a short video showing you the ropes!

Can I have a hint please?

Of course! Check out this part of the hints stream from this week.


Check out the solution stream here.

Experienced challenge — a call for witnesses


So it turns out things aren’t quite what the seem in Graphville… we want you to use graph algorithms to find out further potential witnesses to speak to. Whilst this is bit of a fluke in the data, it’s a great opportunity to try out the Graph Data Science (GDS) library.

Experienced challenge: Find the other witnesses

You will be given hints for some witnesses in the challenge, however there may be some more we’d like to speak to. We would like you to have a go using the Weakly Connected Components (WCC) algorithm to try and identify these potential witnesses to interview.

You’ll need to solve the murder first, and then use that information to help identify the right community.

Why not do a bit of digging. What surprising discovery do you find along the way?

What are we looking for?

  • Use just Facebook check in events for WCC and/or the Gym check-in for the specific witness date!
  • The names of the suspects
  • The names of the other potential witnesses to speak to

The data

  • Please use the load scripts as per the beginner’s challenge

Can I have a hint please?

Of course! Check out this part of the hints stream from this week.


Check out the solution stream here.

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