I'm an Unreliable Narrarator

My name is Tina, and I am a detective. I am trying to find out who stole the smiley face notebook. I works for the FSI, who goes around, finding smiley things that have been stolen. The victim of this crime is a little girl, who loves smiley faces. She really hopes that the FSI can find her notebook and find the criminal.
I was looking at the crime scene (the park), very curiously. This little girl said that she had been drawing smiley faces and rubber ducks in her notebook all morning. She had to go to the bathroom, so she left her notbook, along with her pencil and picnic basket, there. She also bought a water bottle while gone. Then, she said that when she got back, the notebook was the only thing gone.
This is a very hard crime to solve. I stayed there almost all night trying to find out who had stolen the notebook. Now I have some suspects:
Flynn I. Cream- Ice Cream man, who works for the park. He was seen at the crime scene, just a few minutes before it happened.
Bartholemew Bop- Mysterious man who sits under the big tree. He was seen there after the crime happened.
Fern Tweet- Little girl who doesn't like the girl who got her notebook stolen. She frequently goes to the park and whistles a lot.
So, these are my suspects and now I have to figure out who did it. But first, I heard a knock on the door. When I opened it, I saw some police officers. They looked confused and one of them asked me if I liked smiley faces.
"Okay, I did it! I stole the notebook!"
"What?"
"I did it. Here, it's under my floor boards!" It really was there.
I was charged with first degree criminal theif of smiley notebook, (otherwise known as FDCTSN). I was sentenced to work a dull, boring buisness firm for 11 months. That is the worst thing that they could have given me! I will never steal a smiley notebook again.