PHILADELPHIA, USA (AP) — Legal advocates are lining up on both sides of actor Bill Cosby’s appeal as the Pennsylvania Supreme Court prepares to review his 2018 sex assault conviction.

Cosby was the first celebrity to go on trial in the #MeToo era, and his appeal could resolve lingering questions about how the cases should be tried. For starters, the high court will try to clarify when other accusers can testify against a defendant — and when the additional testimony amounts to character assassination.

Public defenders in Philadelphia, in a friend-of-the-court brief filed in Cosby’s appeal, noted that courts have given conflicting guidance on the issue.

“Courts repeatedly fail to analyse how uncharged misconduct is relevant to prove, for example, intent or identity,” the Defender Association of Philadelphia wrote in the amicus brief, one of several filed in the case this past month.

They say the testimony should only be allowed if it’s linked to a single crime scheme, to avoid “the genuine risk that defendants will be convicted for who they are, or for what they may or may not have done before.”

Prosecutors, in a brief filed late Monday, offered several legal justifications for the accusers’ testimony, hoping at least one of them will stick. They said it’s needed to show Cosby’s pattern of behavior, to show the encounter wasn’t a one-time mistake, and to show the complaint wasn’t filed on a whim.

“It is unusual, to say the least, that defendant has been repeatedly … accused of engaging in sexual conduct with unconscious or otherwise incapacitated young women … without any consequences,” the Montgomery County District Attorney’s Office wrote in their response to Cosby’s appeal.

Cosby, 83, will mark two years in prison this month and has another year to go before he can seek parole. However, he has vowed to serve the full 10-year maximum rather than show remorse for what he calls a consensual 2004 encounter with Andrea Constand, a former professional basketball player who worked for his alma mater, Temple University, in Philadelphia.

Cosby won a shot at reversing his conviction earlier this year, when the state Supreme Court agreed to review two central trial issues: the other accuser testimony and Cosby’s claim that a former prosecutor had promised he could never be charged in the case.

Cosby’s lawyers said they relied on that promise when they let him testify in a civil suit that Constand filed in 2005, shortly after the suburban Philadelphia prosecutor declined to arrest Cosby. A successor, Montgomery County District Attorney Kevin Steele, arrested Cosby a decade later after the comedian’s damaging deposition from the lawsuit was unsealed.

The Pennsylvania Attorney General’s Office, in a brief in support of Steele, said the Cosby camp’s decision to rely on an unwritten promise before he testified in such “a grave matter … was unreasonable.”

The Supreme Court has not yet set a date for oral arguments. Other groups filing legal briefs in the appeal include the Rape, Abuse & Incest National Network, known as RAINN; the Pennsylvania Association of Criminal Defense Lawyers; and the Pennsylvania District Attorneys Association.

Cosby was convicted of three counts of felony sexual assault based on charges that he drugged and molested Constand after she came to his house for career advice.

The five other accusers who testified for the prosecution said they believed he also drugged and sexually assaulted them in the 1980s.

Pennsylvania case law suggests that judges should carefully thread the needle when it comes to testimony about “prior bad acts,” allowing it only for a few specific reasons, such as to show a “signature” crime pattern.

Cosby’s trial judge, Montgomery County Judge Steven O’Neill, said their testimony did just that, even if it occurred a decade or two before Constand’s encounter.