VERNON, N.Y. (WKTV) - Joseph Giacona, 13, has been charged with second-degree murder in the death of his father, and police say he will be tried as an adult.

Giacona III is currently being held at a juvenile facility, and from there he is expected to be transferred to another juvenile facility near Albany.

Police say that for the past 8 months, the case against the teen was building. They say they knew they had their suspect, once they found inconsistencies in the stories they had been hearing from the teen.

On January 24, Giacona III called 911, saying that his father had been shot, and for months afterwards, he remained free, even attending school in a new district - Whitesboro.

However, early Thursday morning, he was arrested and charged with second-degree murder, and will become the youngest person ever in Oneida County to be tried as an adult - a decision prosecutors say was a tough one, but was necessary.

"It appears from the scene that the father was sleeping on the couch, and was shot with a shotgun in the head, and to me that is adult behavior," Assistant District Attorney Kurt Hameline said.

Police say they believe they have the gun that they believe the 13-year old used to kill his father.

Other than that, they say this case was built on circumstantial evidence.

"It was very important we cross the T's and dot the I's and get everything done upfront before we go ahead and accuse someone," Hameline said. "We want to be very very careful that we were pursuing the right person."

Because of very little physical evidence, prosecutors say much of this case will be tried on that circumstantial evidence, along with motive.

However, the police did not release any details regarding motive as of Thursday.