There were not, Hannibal felt, enough moments in his life where he got to practice one aspect of his interests. The hospital didn't really have need for him as a psychologist, since Arkham existed and housed a very capable Jonathan Crane. They utilized him as the Head of Diagnostics, and they used his talents as a surgeon. His natural aptitude to dissect the brain was left to the physical when he craved more.
The police contacted him to ask him to assess a girl, and Hannibal jumped at the chance. When he inquired about Crane, he was informed that it was felt the doctor was too close to her to be unbiased. Hannibal wondered if the bias would have worked in favor or against her.
He was provided a file, but chose not to look at it. He would make his assessment of the individual and look at the provided paperwork later if he absolutely needed to. In all honesty, Hannibal felt that he wouldn't need to. He was too good at reading others. He didn't say this to anybody else, though, opting to explain it that he didn't want to have any preconceived notions going in. Being humble generally worked better with law enforcement.
They'd arranged for Hannibal to assess the girl in her room, allowing her to remain unbound. He'd been warned that she was dangerous, and he'd waved them off. Now the door was unlocked and he was permitted entry. A very sad plastic folding chair was set out for him. The door locked as soon as he was across the threshold.
"My name is Doctor Hannibal Lecter." He said as the footsteps faded. Hannibal knew they would not be very far away, close enough to save him if she attacked, though he'd asked the guards to give them as much privacy as possible. They'd told him that her name was Effie, but Hannibal decided to let her introduce herself on her own terms. Sometimes names people didn't want caused blockages.