#25 More lying and buckets

I got the final answer. It turns out that Abe is the thief. Abe is the one that took it without paying for it at school during lunch.

Fill up the 5 gallon bucket.
Pour out 3 gallons into the 3 gallon bucket leaving 2 gallons in the 5 gallon bucket.
Pour the 3 gallon bucket out.
Pour the 2 gallons into the 3 gallon bucket.
Fill up the 5 gallon bucket.
Pour 1 into the 3 gallon bucket.
Pour out the 3 gallon bucket.
You now have 4 gallons in the 5 gallon bucket.

fill up the 7 gallon bucket.
pour 4 gallons out of the 7 gallon bucket into the 4 gallon bucket leaving 3 in the 7 gallon.
pour the 4 gallons out.
pour the 3 gallons into the 4 gallon bucket.
fill up the 7 gallon bucket.
pour 1 from the 7 gallon bucket into the 4 gallon bucket.
pour the 4 gallon bucket out.
pour 4 gallons into the 4 gallon bucket leaving 2 gallons in the 7 gallon bucket.
pour 4 gallon bucket out again.
pour the 2 into the 4 gallon bucket.
fill up the 7 gallon bucket.
pour 2 from the 7 into the 4 gallon bucket.
pour out the 4 gallon bucket.
You now have 5 gallons in the 7 gallon bucket.