Derek's only vaguely listening to the police scanner as he changes, really, and the volume is down low so he barely catches it. It's sort of an early warning system, though it's not technically legal, so he keeps it on all the time.
But he hears it all right - dispatch to the Stilinski house. His first port of call is Scott, to check if Stiles was in school. Logically, he knows that somebody would've texted him if he hadn't showed, they have a system to prevent fuck ups now. Scott says he is, so Derek gets in the Camaro and drives to the school, taking the circuitous route past Stiles' house.
He sees a body bag being lifted into an ambulance and he swallows. He has to get to Stiles. It's an innate need to protect his pack as best he can, because something has clearly gone horribly wrong. He calls Scott again when he gets there because he doesn't want to worry Stiles; he tells them to meet him outside. Derek's probably spent enough time suspiciously wandering around school corridors, he figures.
Stiles doesn't seem surprised to see him, which strikes Derek as weird. Stiles is always surprised that Derek has any kind of presence in his life, really. He's similarly unsurprised by the sirens, and something small inside Derek is screaming that something has really gone horribly wrong here, and get out, get out. These are just teenagers and Derek can't help but feel responsible for them, even for Stiles.
Perhaps, he thinks, standing by the main entrance wasn't the best idea he's ever had, because the police officers immediately approach him. One of them quirks an eyebrow at his presence (which, yeah, basically what he expected) but they're approaching nonetheless. Scott is exuding worry and concern and general anxiety, and Derek has never been more grateful that Stiles is human and can't sense that - although he's probably got a pretty good idea anyway, given how well he knows Scott.
"Stiles," says one of them.
"Yes, Cara?" Stiles grins, and Derek doesn't miss the way the deputy shudders at the use of her first name. Sometimes Derek forgets that after his mom died, Stiles basically grew up in the police department.
She shakes it off, though she looks a little green and her heart's beating too fast.
"Stiles, you're under arrest on suspicion of the murder of one John Stilinski."
Scott makes a sound in the back of his throat, stunned. Stiles grins.
Derek did not see that coming.
"Aren't you gonna read me my Miranda Rights?" asks Stiles, an easy familiarity with the officer. "C'mon, Cara, I know you know how to do your job."
Cara makes a hand gesture and Stiles holds out his wrists to be cuffed. The man standing next to her isn't gentle on Stiles wrists with the cuffs, which makes Stiles huff out, loudly.
"You can trust me, guys. I'm not gonna run anywhere," he says, and Derek wonders if he's in shock. Scott hasn't said anything either.
Stiles is being moved towards the car, and Derek finds himself following. Stiles chatters, a rueful grin on his face as he offers that "It's just like old times, right?" Derek can hear Scott's heart beating and he wonders if the kid is going to have a panic attack, or worse, if he's going to shift here, in the parking lot, where students are rushing out because word has spread: Somebody is being arrested.
Derek feels sick.
He wonders, idly, why they don't feel any pity for the boy, the kid, they just handcuffed and stuck in the back of their car.
He realizes, after a moment, that the evidence must be pretty damning. They'd been so gentle with him, when they'd picked him up to tell him the news. It was not so with Stiles. They knew.
Derek drags Scott to his car, ignoring the look the deputy, not Cara, is giving him. He doesn't give a shit if he's encouraging truancy or looks creepy as fuck, right now, he needs to sort this out. Derek texts everyone else, he figures this is the sort of thing the administration will forgive. It's not every day one of your friends gets arrested. For murder.
Of his own father. Jesus, shit, Derek didn't even know what to do with that. Stiles wouldn't kill the Sheriff - he spent half his time lying to him to keep him safe, feeding him green vegetables and watching his alcohol intake.
It was so far beyond the realm of normal, but Stiles hadn't even tried to deny it.
And somehow that worried Derek more. The whole exchange, Stiles had seemed completely centered. Nothing that was happening was unexpected. He had known this was coming, he'd known why. That was the thing that left Derek with a sour taste in his mouth and some terrifying questions to answer.
Scott is silent the whole way back to Derek's place. That's fine with Derek; silence is the kind of thing he can work with. But Scott has no idea what's going on, that much is obvious, and it worries Derek. Because Stiles isn't usually predictable, but this is so utterly out of left field that Derek doesn't know what to do. Has he been carting around a kid for months who could be a murderer? Is Stiles going to spill all of the important shit to the cops?
Derek doesn't know what to fucking think, any more. His knuckles are white around the steering wheel and if he's not careful he's going to break something. And he really likes this car.
His wheels skid when he pulls up, too rough on the handling of the car, and he slams the door when he gets out.
Scott opens his mouth, and Derek snarls at him.
Scott shuts his mouth with a click of his teeth.
The rest of the pack pull up, get out of their cars. Boyd and Erica are still notably absent, leaving Derek off balance.
Jackson looks pissed, but there's an undertone of worry thrumming through all of them.
"We saw the cops," Isaac says. "What did Stiles do?"
"Murdered the Sheriff."
Scott clears his throat. "Allegedly."
"His dad?" Jackson scoffs. "No way, Stiles would never - he's like a health freak about that guy."
Scott shrugs. "He didn't fight it."
Lydia arches an eyebrow. "Was he surprised?"
There's a beat of silence. Derek shakes his head.
"Well, then." Lydia says with a note of finality. "I'm missing AP Calculus."
She starts moving towards Jackson's car.
"Stiles has been arrested!" Scott bursts out. "Don't you even care at all?"
Lydia smiles saccharinely. "No." Jackson smirks, and follows Lydia back to his car.
Derek is endlessly frustrated by the smug look on his face as he watches them drive away.
"I'm going to visit him," Scott says. "They allow that, right?"
Derek nods idly. He'd been allowed visitors in his brief acquaintance with Beacon Hills holding cells, but he hadn't had any.
"Well, we'll figure out what's going on, right, Derek?"
"I'm going to his house," Derek says, and leaves Scott standing there with Isaac.
"He was my ride," he hears Scott say as he drives the Camaro away.
Derek figures Scott will work something out.
Stiles' house is taped up, pretty much what Derek expected. He briefly considers climbing through his bedroom window but it is broad daylight and he doesn't want to implicate himself. One investigation for homicide is more than enough for a lifetime.
Later, he goes by the police station. He can't help himself, knowing Stiles is there but not knowing why it's like an itch under his skin. That, and he can't be bothered to go to the Argent's to interrogate Scott.
He tells his name to the woman at the desk - different than the one he charmed last time, he notes, grateful, who raises an eyebrow at who he wants to visit. †Stilinski has had a lot of visitors today," she says, before passing the book over to Derek, pointing at where he should sign his name.
Scott, as expected. Scott's mom - pretty much expected too. There's a name he doesn't recognize, and he frowns at it, trying to place it as he signs his name. He'll ask Stiles about it, he decides, as the woman gestures him through. She's resigned, and a little pale, and Derek can smell an undertone of sadness. It's likely, he thinks, that the Sheriff's death will have had an even harder impact tomorrow. Better to get this out of the way.
"Derek, buddy, I get a visit from you?" Stiles says, grinning wide, when Derek enters the room.
"Did you kill him?" He asks, as soon as he's seated, a guard in the corner of the room.
"Getting straight to the point, huh, Derek?" Stiles says, without even flinching. It's remarkable.
Derek growls. "Did you kill him?" He repeats.
Stiles shrugs. "Sure."
His heartbeat is steady, and Derek's heart is breaking. Because Stiles is just some kid, he shouldn't even be involved with all of this werewolf stuff, and what if it's Derek's fault?
Admittedly, Derek hadn't thought prior to that that he was capable of making people homicidal, but he'd been wrong about Peter, too. Derek had liked Stiles, on the rare occasion that he'd shut up enough for them to have a conversation.
"Why?" Derek asks.
Stiles smiles. "Seemed like a good idea at the time," he says, offhandedly, but Derek can hear the way his heartbeat stutters.
"No, it didn't."
"Okay, so I thought about it beforehand," Stiles says, twisting his lips. He shrugs again.
Derek stares at him. This isn't the Stiles he knows. It isn't.
"Who's Mark Woolham?" He says.
Stiles frowns. "I have no idea."
"He came to visit you."
"Oh! Peter! Right? He's still a missing person?"
"What did Peter have to say?"
Stiles grins, looking a little wicked. It's not a look Derek's used to on him, and he fights off a shudder.
"Welcome to the club," Stiles says.
Derek swallows.
"I'm done here," he tells the guard.
Stiles calls after him, and Derek chooses not to hear the words. He doesn't think he can cope with it right now.
The woman at the desk tells Derek Stiles' court date, and that he'll be tried as an adult. Derek nods. He has a feeling Stiles is going to plead guilty anyway. There was no use pretending he hadn't done it.
They'll visit him in prison, Derek decides. The whole pack will. They've got to try and figure out who the hell Stiles is.