Emily says the ballistics report confirmed the copycat was using a ".44 calibre Bulldog" like David Berkowitz did. Ballistics can confirm the calibre, but not the model of the handgun. "Bulldog" isn't a type of bullet, it's a short-barreled revolver.
Garcia says she used the existing sketch of the unsub to start the facial recognition search. FR only works on clear photographic images, not on drawings.
Albert DeSalvo was not the Boston Strangler.
Due to the lack of any evidence connecting him to the crimes, he was never even charged with the murders. His life sentence was for sexual assaults.
Strangling his victims with stockings was not the Boston Strangler's signature. His signature was using items from the victim's home and even clothing to strangle them (eg, dressing gown belt, stocking, pillowcase), and leaving it tied in an ornate bow around their throats.
If the unsub was properly recreating the murders of Jack the Ripper he would have killed prostitutes, however there was no mention of any of the victims being part of the oldest profession.
During the second dream sequence, while Prentice is shooting at the unsub, we hear empty shell casings falling on the floor but the casings that are shown have bullets in them.