I’m confused

Me too pls

Dark haired persecutor was taken care of in middle school by blond hair character's mother
She got burned in a church fire
Dark hair felt indebted to blonde hair
Saw him through school up until when he's supposed to enter into university
Now Dark hair is trying to investigate the church fire because he doesn't believe it was a suicide.

Ok but who were the 2 people in the end?

The friend from University that dark hair now calls family
The woman is the friends mom, who I think (SPOILER) is the Cecilia the was the accomplice of blonde hairs mom who died in the fire
I THINK SHE KILLED HER AND TOOK THE FILE

Thank you so much everyone! Is Cecilia the prosecutor’s mom? I think I’m confused there. Is he finding out his mom killed the blonde woman?

Kinda
Its just like one considering their bestfriends mom their own mom