SL-9 Incident

The SL-9 Incident, colloquially known as the Joe Darke Killings, was a series of murders that culminated in the killing of prosecutor Neil Marshall in the Los Angeles Criminal Affairs Department. This led to the trial of Joe Darke, who was found guilty and executed.

Early killings
The incident began when Darke accidentally ran over and killed a man while driving his car. He began to panic, and he killed an eyewitness to the crash in a fit of paranoia. He then killed more people as they stumbled onto the scene before escaping from the scene of his crimes.

In response to this, the police department set up a team of detectives consisting of Bruce Goodman, Jake Marshall and Angel Starr, overseen by legendary detectives Damon Gant and Lana Skye. Darke soon turned himself in and the matter seemed to be finished. Jake's brother Neil was assigned as the prosecutor for the case.

Murder of Neil Marshall
However, on a stormy night not long afterward, Darke escaped from the interrogation room of the police station while being questioned by Damon Gant and Neil Marshall, and he blindly ran into the joint office of Gant and Skye. Ema Skye, Lana's younger sister, was there, but before Darke could get to her, he was attacked by Neil Marshall, who had caught up with him. While it was too dark for Ema to see the faces of the two men, she saw that one of them was in control, holding a knife over the other. She assumed that the figure was Darke, and she pushed the man to the floor, knocking over an unstable jar. However, she had actually pushed Neil.

After all three of the people lost consciousness, Gant entered the room. Seeing that he could use the situation to further his career and control the prosecutor's office, he cut out a piece of cloth from Marshall's jacket that had Ema's handprint on it; he then impaled Marshall on his ceremonial suit of armor. He also wrote Ema's name on the jar (which had survived the fall) and broke it into shards. He then put the section of jacket and a piece of the jar in his safe as insurance.

Lana Skye then entered the room, and after looking at the crime scene, she assumed that Ema had accidentally pushed Neil to his death. She took a picture of the crime scene as she discovered it, with Marshall's body impaled on the suit of armor. She then asked Gant to help her cover up the crime scene and he agreed. They moved the body and the unconscious Darke to the other side of the room, and planted the broken tip of Darke's knife into Marshall's wound to implicate Darke as the killer later. The plan succeeded, and the police arrested Darke again and charged him with the murder of Neil Marshall.

Trial
Miles Edgeworth replaced Marshall as the prosecutor in charge of the trial against Darke, but he was concerned about the amount of evidence that was found. Thus, he called Ema Skye as a witness to the crime. She tried to explain what had happened but she was too frightened to speak in court. She had drawn a picture to show what she had seen on the back of the evidence list, but Gant had torn it in half, and the half that showed the unstable jar was hidden in Gant's desk drawer. There was enough evidence to charge Darke for the murder, and he was found guilty and sentenced to death.

Aftermath
Immediately after the trial, Gant was promoted to Chief of Police. He then moved Lana to the Prosecutor's office as Chief Prosecutor, and used the cover-up to blackmail her into doing what he asked. The three detectives who had been assigned to the case had their suspicions as to the legitimacy of the verdict, but Gant soon fired Starr and demoted Jake Marshall to a patrolman several months after the trial. He did keep Goodman at his post however, but only reduce suspicion as to his motives. The trial also caused persistent rumors about Edgeworth falsifying evidence.

Thus, Gant obtained complete control over law enforcement in Los Angeles.

Resolution

 * Main article: Rise from the Ashes

Two years later, the evidence from the SL-9 Incident was to be removed from the evidence room, a practice known as evidence transferal, which would make it difficult to reopen the case. However, Starr and Jake Marshall still suspected that something had gone wrong in the trial, so Marshall convinced Goodman to take action. Goodman accompanied Gant to the evidence room and asked him to reopen the case. Fearing that his murder would be exposed, Gant hastily stabbed Goodman with Darke's switchblade knife, killing him, and arranged with Lana Skye to move the body using Edgeworth's car. Gant also told Lana to stab Goodman with Edgeworth's knife to throw the scent off further. However, Starr caught Lana in the stabbing act; she became the prime suspect in Goodman's murder.

Lana Skye's attorney, Phoenix Wright, eventually came up with a clever plan to cause Gant to reveal himself as the killer in the murders of both Neil Marshall and Bruce Goodman, and the case was finally solved for good.