Courtyard (prison)

The courtyard of the prison is a place for the inmates to go outside without leaving the compound. It is bordered by an electrified fence that has a door leading to the warden's office. The courtyard also contains a well, a pond in which resides prison warden Marī Miwa's pet alligator Ally, and the prison's circuit breaker room. The Berry Big Circus performs a show in the courtyard every month for the prisoners' enjoyment.

The Supplier
When Ryōken Hōinbō was sentenced to prison, he threatened Miwa, telling her that he had henchmen working for him outside. In addition to special privileges, Hōinbō had Miwa arrange a smuggling route for various goods that the other prisoners wanted. Each week, Miwa would have Frank Sahwit use the circuit breakers to turn off the power so that the security cameras and electrified fence would cease to function. Miwa would then drop the goods down the well, using a perfume to signal Hōinbō's dog, Kuro, to pick them up. The well had a tunnel leading to the prison cell of Shūji Orinaka, allowing Kuro to pick up the goods and bring them to Hōinbō's cell. Sahwit would later restore the power, and Miwa would correct the timestamps on the cameras.

Breaking point

 * Main article: The Imprisoned Turnabout

Miwa's fear of Hōinbō came to a head during one of the Berry Big Circus's visits in March 2019. The show that month was a love story involving Dali the elephant and Regent the tiger, with a villainous monkey played by one of the employees, Sōta Sarushiro. During the climax of the show, Dali would blow Sarushiro away with the power of love. To facilitate the stunt that would be needed to pull this off, Sarushiro built a pulley system over the well using weights attached to his foot via a rope. A second rope would be attached to a stopper, allowing him to remove it at the right time and send himself flying when the weights fell down the well.

Two days before the show, Manosuke Naitō was arrested and detained in the detention center's holding cell. Over the following two days, Miwa discovered that Naitō was playing correspondence chess with Hōinbō, and brought him into her office for questioning on the night before the show. During the questioning, she snapped and killed Naitō using a knife that had been confiscated from Hōinbō. Sahwit cut the power as usual, though he had to move a cart of apples to do so, bringing it within Dali's reach so that she ate all of the apples.

Miwa took advantage of the smuggling route to bring the body to Hōinbō's cell and pin the murder on him, which would cause him to be transferred to a different prison. To give herself an alibi, she replaced the weights in Sarushiro's contraption with the body, and hid the weights in some grass. The body would fall and be picked up by Kuro during the show, when everyone except Hōinbō and Sahwit would be watching the show. She hid the murder weapon inside Ally.

The body was discovered the next morning in Workroom A, attracting the attention of Miles Edgeworth, the prosecutor in charge of Naitō's trial. The door from the prison hallway to the courtyard was locked when he arrived.