WHY IS MY Squirt Gun Missing!?

I had a good way to keep the cat off the computer. I went to the dollar store and bought a squirt gun. Now the weapon is missing!
There are three likely suspects.

One

The cat, he has every reason to benefit from this theft.
TWO

The boy.. he thinks what is mine is his.
THREE

THE DOG...
he has a lot of hidden resentment. Oh he pretends to be the loving family pet, but I wonder..
I will get back to you on this.