Psychological thriller / read in 2014 (ish) / detectives are trying to find a killer who burns his victim’s bodies

[Charmaine]

One victim is found in a stairwell and another in an elevator. I think the killer and victims are linked to an orphanage. It's set in a US metro area but can't remember which...

Thank you!

[Lobstergirl, au gratin]

Set where? Country/region/city etc.

[Charmaine]

Lobstergirl wrote: "Set where? Country/region/city etc."

I updated the post but I believe it's set in the US, I think in a large city. Thank you!