Murdering at the school

The revelation

"HENRY!"- said Charles, in happiness tears, running to hug his son
"My God..."-whispered Frank
All the cops in the delegacy were confused. And then, Henry pointed a gun to Charles before he reached him. All the cops pointed his gun to Henry.
"DON'T SHOOT"- said Frank to the cops
"Where did you got that gun?"-asked Charles to his son
"From the cops I killed in the school canteen."- answered Henry
"Is this some kind of sick joke, Henry?"- said Charles- "How are you even supposed to know that?"
It was that moment that Frank realized what was going on. He was the killer. He didn't knew how, but he was.
"I am the killer you and uncle Frank were looking for, dad"- said Henry
"No. That's not possible."- said Charles
"Yes, it is. I started planing this two years ago. Don't you remember I was learning to do statues dad? I did one. But instead of using ink and that stuff, I used human skin, hair and organs. Don't you remember dead bodies disappearing from the delegacy morgue, dad? Then I burned it and made sure my DNA was all over it. After I "died", the place where my burned little toy was found was always isolated. I lived there. I knew what would be the headmaster's reaction and that he and Percy were very close friends. But I needed someone who would help me, someone who would told me what was happening. Jimmy was the solution. The day after I "died" I send him a ticket pretending I was his sister. I told him that his sister wanted to explore that place and he got there in a hurry. I told him what I did and then I told him if he didn't help me I'd kill his sister. And then you seiged the school. I knew you were going to do that soon, but not that night. I saw you coming and ran to the canteen. When the first two cops appeared, I showed up and told them to follow me to find the killer. They did it, and I killed them with a knife. I was preparing the heads and the candles, because I knew you were going to check on the cops, when I got a visit from the headmaster. Let's just say that the heads got one more friend. I was thinking of a way to get out of there without you arresting me. Then, I remembered Kyle. He was not there when I died! My plan was to incriminate him. So I played the song he was always playing on the piano. I knew what was your reaction and got out of the room by the window. You were so nervous you didn't even checked the digital impressions in the piano. I have to admit I was scared because everything could go wrong, but I made it. And then I got here."
"Why son?"- asked Charles
"Because of our country. This needs to go to the news from all over the world. People need to know that there are psycho's in Portugal too! They need to fear our country. It's the first step to the world domination"- answered Henry
"You're mad, son. That doesn't works like that."- said Charles
"Kyle disappeared"- said Frank- "Do you have anything to do with it?"
"Oh, your son. Me and Jimmy have a secret place. While you were playing detectives, your son received a ticket from me telling I was alive and to meet me at the park. When he got there, Jimmy drugged him and took him to the secret place."- answered Henry
"Why did you go to the delegacy, son?"- asked Charles
"To finish my job. You will have to kill me, dad. Imagine the news all around the world. Detective father kills psycho son. Do it dad. Kill me."- said Henry
"I will not kill my own s..."- said Charles
Henry shot a random cop.
"If you don't kill me I will kill every single cop who is here"- said Henry
"But..."- said Charles
Henry shot another cop.
"That's enough!"- said a cop
"NOOOOO"- shouted Charles jumping in the front of his son. The shot was in the head. Charles was dead.
"CHARLES"- shouted Frank running to his best friend dead body.
"NOOOOOOO"- shouted Henry- "YOU WERE NOT SUPPOSED TO KILL HIM"
Henry still shot 3 or 4 cops (including the one who killed his father) before getting shot in the head and dying.
Frank was shocked looking at Charle's dead body.
"No"- said him, after standing on his knees and crying - "I will not lose more people today. We need to track down Kyle. And I know exactly how to do it."
With Henry's phone he phoned Jimmy. Another cop was trying to track down Jimmy's location.
"I know you told me to kill him. I am trying to, but I can't."- said Jimmy
Frank panicked even more when he heard that.
"I did it"- said the tracker
Frank instantaneously turned off the phone, gave a last look to Charles and Henry, and said:
"C'mon, we have no time to lose."