Luke woke up the next morning feeling restless. The case was getting to him, and he couldn't shake the feeling that they were missing something. He decided to go for a run, hoping to clear his head.
As he jogged through the park, he saw Stella sitting on a bench, staring off into space. He ran over to her, concerned.
"Stella, are you okay?" he asked.
She looked up at him, tears in her eyes. "I'm sorry, Luke. I can't do this anymore."
"What do you mean?" he asked.
"I'm the one who killed your grandmother and all those other people," she confessed.
Luke was stunned. He couldn't believe what he was hearing. "Why? Why would you do something like that?"
Stella took a deep breath. "My family was killed by a gang when I was a child. The police never found the killer, and I've been obsessed with finding justice ever since. When I saw the first victim, I knew it was the same gang. I couldn't let them get away with it again."
Luke was speechless. He couldn't believe that someone he trusted and cared about could do something so terrible.
"But why did you kill my grandmother?" he asked.
Stella looked away. "I didn't mean to. I thought she was one of them. I saw her walking near the gang's hideout, and I thought she was there to spy on them. I didn't know she was your grandmother until after I did it."
Luke shook his head in disbelief. "I can't believe this. I trusted you. I cared about you."
"I'm sorry, Luke. I really am," Stella said, tears streaming down her face.
Luke stood up and walked away. He didn't know what to do or where to go. He felt like his whole world had been turned upside down.
He went back to the police station and handed in his resignation. He couldn't work with someone who had betrayed him and killed innocent people. As he was packing up his desk, he found a file that Stella had left behind.
He opened it and saw that it contained evidence that the gang was planning a major heist that night. He knew that he couldn't let them get away with it.
He called his former partner, Detective Rodriguez, and told him everything. Rodriguez promised to send backup and get there as soon as possible.
Luke drove to the location where the heist was supposed to take place. He waited in his car, watching as the gang members started to arrive. He could feel his heart racing as he realized that this was his chance to catch them all.
As the gang members started to break into the building, Luke got out of his car and ran towards them, gun drawn. He could hear sirens in the distance, and he knew that Rodriguez and his team were on their way.
The gang members turned and saw Luke, and they started to run towards him. Luke fired his gun, hitting two of them before they could reach him. The others scattered, but Luke kept firing, determined to catch them all.
Rodriguez and his team arrived just as Luke was finishing off the last of the gang members. They were impressed by his bravery and skill, and they told him that they would make sure he got the credit he deserved.
Luke realized that he had found his true calling. He may have lost his trust in people, but he had gained a new purpose in life. He would dedicate himself to fighting crime and making sure that justice was served.