A disturbing discovery inside an apartment building sent shock waves through a Brooklyn neighborhood.

"You never who’s behind closed doors," Manuel Aponte told NY1.

Aponte is still is disbelief after hearing his friend, Kawsheen Gelzer, 40, was found dismembered inside a freezer.

"When I found that out, I was like it can’t be him. It can’t be him. And that’s exactly who it was," Aponte said.

NYPD officers did a wellness check at the apartment of Heather Stines, 45, Monday night. That’s when police say they found dismembered body parts — including a head and limbs — in separate black bags inside her freezer.

Detectives say Gelzer was identified by his fingertips.

"I hope they find out who really did it because he didn’t deserve that," Aponte said.

Aponte told NY1 that he had not seen Gelzer in a few months and started to worry.

"Likable guy. Lovable guy, really. Everyone liked him in the neighborhood," Aponte said.

The Brooklyn District Attorney's office says Stines had three open warrants at the time of her arrest. She was ultimately charged with concealment of a human corpse and arraigned Friday morning.

"Whoever did it will get their day. Somebody's going to pay for it," Aponte said.

Officials say Gelzer’s remains were transported to the office of the chief medical examiner, where Gelzer's official cause of death will be determined.