These lying thief riddles are fun and tricky logic puzzles that will test your brain. In each puzzle, you interrogate a number of suspects, knowing that some of them are lying, and use that information and your deduction skills to find the true culprit.

## Lying Thief Riddle #1 (Easy)

There are 3 suspects in a robbery, one of which is the true culprit:

- A: “I didn’t do it.”
- B: “C did it.”
- C: “B is lying.”

You know that two suspects are lying and one is telling the truth. Who is guilty?

#### Click for Solution to #1

A is guilty.

Let’s say B was telling the truth, that C did it. But then A must be lying, which would mean A did it. This is a contradiction, so B must be lying.

If B is lying, then C’s statement is true. Therefore C is telling the truth and the other two are lying, which means A is guilty.

## Lying Thief Riddle #2 (Medium)

3 suspects in a robbery are being interrogated: A, B, and C.

You were only able to catch A’s statement: “B is the thief.”

However, the detective in charge of the investigation made an interesting remark: “It’s funny, out of the three suspects, only the actual thief told the truth.”

With the detective’s remark, you were able to figure out the culprit without hearing the other suspects’ statements. Who is guilty?

#### Click for Solution to #2

C is guilty.

For A to be telling the truth, A would have to be the thief. But this is impossible because A claims B is the thief. Therefore, we know:

- A is not the thief, since A is lying
- B is also not the thief, since A’s claim that B is the thief is a lie

This leaves just C, who must be the thief.

## Lying Thief Riddle #3 (Medium)

There are 3 suspects in a robbery, one of which is the true culprit:

- A: “I didn’t do it. C didn’t see who did it.”
- B: “I didn’t do it. C did it.”
- C: “I didn’t do it. I saw A do it.”

You know each suspect told exactly one truth and one lie in their statements. Who is guilty?

#### Click for Solution to #3

A is guilty.

Start with B’s statements:

- Let’s assume the first part is the lie. Then the first part indicates B is guilty. But the second part must be the truth, indicating A is guilty, which is a contradiction.
- This means the first part must be the truth, so B didn’t do it. And the second part is a lie, so C also didn’t do it. Therefore A is guilty.

We just need to confirm there is no contradiction among the other statements.

C’s statements: Since A is guilty, the first part is true, C didn’t do it. Then the second part must be false, C did not see A do it – this is possible even if A is guilty, because C could just have not been there to witness it.

A’s statements: Since A is guilty, the first part is false, A did it. Then the second part must be true, C didn’t see who did it. This is consistent with C’s second statement being false. Everything is consistent with A being the culprit.

## Lying Thief Riddle #4 (Medium-Hard)

A watch, a laptop, and a purse are stolen by three different thieves. The three suspects are apprehended, and we know each stole one of the items, but we don’t know who stole what.

- A: “C stole the laptop.”
- B: “C stole the purse.”
- C: “I did not steal the laptop or the purse.”

You also learn that the watch thief lied and the laptop thief told the truth.

Who stole which item?

#### Click for Solution to #4

A stole the watch, B stole the laptop, and C stole the purse.

Reasoning:

- A cannot be the laptop thief, because the laptop thief told the truth, and A claims C is the laptop thief, which would be a contradiction.
- C cannot be the laptop thief, because the laptop thief told the truth, and C claims to not be the laptop thief, which would be a contradiction.
- Therefore B is the laptop thief.
- Since the laptop thief told the truth, then C is the purse thief.
- This leaves A to be the watch thief.

## Lying Thief Riddle #5 (Easy)

There are 3 suspects in a robbery, one of which is the true culprit:

- A: “I didn’t do it.”
- B: “A did it.”
- C: “I didn’t do it.”

You know that two suspects are lying and one is telling the truth. Who is guilty?

#### Click for Solution to #5

C is guilty.

If B were telling the truth (that A did it), then C would also be telling truth. But we know only one person is telling the truth. Therefore B is lying and A didn’t do it.

If B did it, then both A and C would be telling the truth. But we know only one person is telling the truth. Therefore B didn’t do it, which just leaves C.

## Lying Thief Riddle #6 (Medium)

There are 4 suspects in a robbery, two of which are the true culprits:

- A: “B and C did it.”
- B: “A and D did it.”
- C: “It was A and me.”
- D: “It wasn’t me.”

You know the two culprits were lying and the others were telling the truth. Which two are guilty?

#### Click for Solution to #6

B and C are guilty.

If C was telling the truth, C’s statement would make C one of the culprits. But the culprits lied, which is a contradiction, so C could not have been telling the truth – and C is one of the culprits.

This also means A cannot be the other culprit, since C had to be lying.

A must then be telling the truth, which means B and C were the culprits.