I don't know how I got it so wrong. This whole time I was convinced Mr. Greene was the killer... because why? He was a grumpy weirdo? I supported my assumptions with confirmation bias... and now he'd dead. 
Batgirls #9 is an issue of the series Batgirls (Volume 1) with a cover date of October, 2022. It was published on August 9, 2022.
Synopsis for "Bat Girl Summer"
It's summertime in Gotham. Cassandra has discovered a love of reading and begun hanging out at Dhaliwal-to-Wall Books, while Stephanie is still convinced their neighbour Mr Greene is the Hill Ripper and continues to spy on him.
The Batgirls capture KGBeast, but in the process Stephanie is knocked off a roof by an unidentified flying figure and falls into a dumpster. She finds a letter addressed to Mr Greene and investigates the trash, looking for proof that he is the Ripper. They discover Greene's body, clearly stabbed to death, and realise that he is a victim, not the killer. The Batgirls quickly gather clues from his corpse and find that one of his eyes has been replaced with a false one, which they take from the crime scene. They depart just as the GCPD arrive.
Back at the loft, Barbara opens the false eye and finds a message inside written in a cipher. Stephanie volunteers to decode it, feeling guilty that she suspected an innocent man of being a murderer solely because he was antisocial and weird. Meanwhile, Killer Moth watches them from the next building.
Appearing in "Bat Girl Summer"
Featured Characters:
Supporting Characters:
Antagonists:
- KGBeast (Anatoli Knyazev)
- Killer Moth (Drury Walker) (Cameo)
- Mister Fun/Hill Ripper (First appearance) (Cameo)
Other Characters:
- Mr. Dhaliwal
- Gotham City Police Department
- Grace O'Halloran
- Roky
- Walter Arnold Greene (Dies) (Full name revealed)
- Dick Grayson (Mentioned only)
- The Saints (Mentioned only)
- Spellbinder (Charles Dante) (Mentioned only)
- Tutor (Cody Kline) (Mentioned only)
- Edgar Allan Poe (Mentioned only)
Locations:
- Gotham City
- Gotham Clock Tower (Cameo)
- The Hill
- Dhaliwal-to-wall Books
- Truffles
- GCPD Headquarters (Mentioned only)
Items:
Vehicles:
See Also