Trouble in school

Sam knew there was trouble coming as soon as Mrs Thomas closed the door. She switched on the light and a dim light spread through the room. Quickly, but carefully Mrs Thomas walked to her desk and sat down in her chair. An awkward silence filled the room.
Sam stood waiting. Finally Mrs Thomas spoke a word. “Sit,” She said, without anger, without happiness, without emotion.
“What is this about, Mrs Thomas?” Sam asked.
“Two weeks ago Mr Lee confiscated your phone. Correct?” She replied.
“Yes, he did,” Same answered.
“Well do you know where he kept it?” She said.
“No. Not really, I assumed he kept it in his classroom or maybe at his house.” Sam replied.
“Last night Mr Lee’s wife was murdered,” She revealed. “They have only one suspect, Mr Lee. But I don’t think he did it.”
“Well, why are you telling me this, miss?” Sam worryingly asked. “I had nothin’ to do with it.”
“You see I don’t think that’s true. I think you were there last night,” She accused Sam. She leaned back in her chair, proudly, as if she had figured it all out.
“Mrs Thomas I have no idea what you are talking about… You have no proof… You are just making assumptions,” Sam hesitated. He didn't really care: he was slouching in his chair and fiddling with a pencil. Sam had a history of bad behavior. He had always got into fights and arguments but in the end he had convinced the teachers that it wasn't his fault.
“Of course I have proof,” She replied. She picked up her phone and dialed a number. Sam’s pocket started vibrating and his phone was ringing.
“You broke into that house, Sam. To get your phone back. But Mr Lee’s wife saw you. So you picked up a knife and you killed her,” She said proudly.
“No… I would never do that,” Sam replied
“But you did. You murdered a woman. For a phone,” She said. The corner of her mouth was turned up in one of her grins, the pride radiating of her. She never liked Sam. He had always manipulated people into believing him when he lied. She was happy she could finally expose his true nature. Sam had no words to speak. He was calm. He put down the pencil and straightened his posture. He looked at Mrs Thomas directly in her eyes. “You did it, didn't you?” She questioned. He stayed quiet. “You killed her,” She exclaimed.
"Alright! I’ll tell you what happened,” He replied. “Mr Lee had kept my phone for almost two weeks. That wasn't fair. Of course I was angry,” He moved closer to Mrs Thomas. “But not enough to kill his wife,” He said.
“You’re not lying your way out of this one, Sam,” She intervened.
“Just let me finish. I decided that I would go and retrieve my phone. I looked everywhere in his classroom and couldn’t find it. I concluded it was at his house,” He explained.
“So you broke into his house, stole your phone and killed his wife. You’re going to be punished, Sam,” She interjected.
“No! That’s not what happened,” He shouted. “I went to his house and picked the lock with a paper clip and broke in. I looked around his whole house and it was nowhere to be found except for his bedroom. I opened the door and it made a creaking sound. I looked inside and saw Mrs Lee sleeping in her bed and my phone was across the room,” He explained.
He pictured the story in his head. He crept slowly and quietly into the room like a lion stalking its prey. Sam reached out to pick up his phone and Mrs Lee suddenly rolled over on her bed. He stood as still as a statue. She stopped moving and was still as if she was dead. He picked up his phone and walked towards the door but accidentally kicked the bed. His heart was beating as fast as the hooves of a horse on a racetrack. Mrs Lee got up as quick as lightning and screamed. He ran out the house with his phone.
“Do you really expect me to believe that, Sam?” She asked. “How do you account for Mrs Lee’s death?” She questioned.
“It’s the truth, I swear!” He exclaimed. “As for Mrs Lee, when I left the house I saw Mr Lee walk into his house. I heard shouting and I assumed they were just arguing. Then suddenly it was silent. I figured it out but was too scared to do anything…” Sam choked. “I know it was my fault… I should have done something… I’m sorry,” He said with great remorse in his eyes.
“No… it’s not your fault. I’m sorry for accusing you, Sam. It was Mr Lee. You have to tell the police,” She replied.
“No!” He exclaimed. “Please don’t make me tell them. I broke into Mr Lee’s house. They will arrest me! Mr Lee is being convicted anyway. Please don’t tell anyone,” He begged.
“Alright. I won’t tell anyone but you shouldn't have stolen your phone back. You can’t just break into peoples’ houses like that, Sam,” She explained.
“I know. I’m sorry,” He said with an apologetic voice.
“Alright. Go home Sam. Mrs Lee’s death was not your fault,” She said.
“Thanks miss,” He replied
Sam didn't go home. He headed towards the police station. He sat on a bench nearby and waited. A police car had stopped in front of the station. An officer got out of the car and pulled someone out of the backseat. It was Mr Lee. He was handcuffed and bent over. He stopped walking toward the police station when he noticed Sam. Sam waved his phone at Mr Lee and smiled. He walked away. “Oh my God. It was him!” Mr Lee exclaimed and started struggling to get out of the officer’s grip.
“Calm down, sir,” said the officer.
“He killed my wife! He killed her! Go arrest him you idiot!” Mr Lee continued to shout and struggle. He escaped the officer’s grip. The officer pulled out a taser and shocked Mr Lee. He fell to the ground and shook violently like a rattle snake’s tail. Sam heard everything but didn't look back. He smiled and continued walking. He knew he was going to get away with murder.