In a 'Harry Potter arrested' fanfiction, the plot might revolve around a new law that has been passed. Harry, being a vocal opponent of this law which he believes restricts the rights of certain magical creatures, gets arrested for civil disobedience. His arrest then becomes a rallying point for other wizards and witches to fight for justice and change the unjust law.
Maybe Harry gets arrested because he's suspected of being involved in a plot to overthrow the current wizarding government. Some powerful wizards, fearing his growing influence and popularity, frame him. In the fanfiction, it could show his struggle to clear his name and expose the real conspirators, all while being locked up and facing interrogations.
False accusations are very common. Usually, Harry is wrongly blamed for something he didn't do, like being involved in dark magic activities.
A new dark wizard or witch could be the main antagonist. This character, jealous of Harry's fame and power, creates a situation where Harry is framed for a heinous crime. They then ensure his arrest so that they can take over the role of the 'chosen one' in the eyes of the wizarding public and start spreading their own brand of dark magic.
One possible plot twist could be that Harry was set up. Maybe there was a powerful dark wizard who wanted to get rid of Harry and framed him for Voldemort's death in a way that made it seem like a cold - blooded murder rather than a heroic act. Another twist could be that the wizarding world has turned against Harry because they fear his power after defeating Voldemort and use this arrest as a way to control him.
Maybe Harry accidentally frames Weasley for something. It could be due to a misunderstanding, like a spell gone wrong that makes it seem like Weasley was involved in some illegal magic use.
One possible plot could be that evidence of her illegal use of power and abuse in Hogwarts is finally uncovered. Maybe a student bravely comes forward with proof of her cruel punishments and false accusations. This leads to the Ministry of Magic having no choice but to arrest her.
Maybe Damian is arrested for pokemon poaching. He could have been hunting down endangered pokemon species in a protected area. The fanfiction could then focus on the legal process he has to go through, like facing trial and the evidence against him. Also, other characters might try to find out if he was acting alone or part of a bigger poaching ring.
Well, one possible plot could be that Santana gets arrested for standing up against some form of discrimination in her school or community. In the Glee universe, she was always a strong character who wasn't afraid to speak her mind. The fanfiction could explore how her friends in the Glee club react to her arrest. Do they stage a performance to raise awareness about the situation she's in? Or perhaps they try to find legal help for her. It could also delve into Santana's own thoughts and feelings while in jail, like her fears and hopes for the future.
One possible plot could be that mankae is wrongly accused of a crime. Maybe he was at the wrong place at the wrong time. For example, he was near a store that got robbed and due to some misunderstandings, the police think he was involved. So he gets arrested and has to prove his innocence throughout the fanfiction.
One possible plot could be that Harry Potter finally has the courage to report the Dursleys' abuse to the proper authorities. Wizards from the Ministry of Magic, after getting involved, find evidence of the emotional and physical abuse Harry endured over the years. The Dursleys are then arrested and Harry is placed in a more positive and caring environment within the wizarding world, perhaps with the Weasleys.
One possible plot could be that Dumbledore is framed for a crime he didn't commit. Maybe there's a dark wizard who has managed to plant false evidence against him. For example, evidence that he was involved in some sort of dark magic plot. Another could be that the Ministry of Magic, fearing his power and influence, decides to arrest him on false pretenses to gain more control over Hogwarts. This could lead to a lot of chaos in the wizarding world as Dumbledore has many allies and supporters who would not stand for his unjust arrest.