The case against Sean Ellis was ‘tainted’ by significant police corruption and prosecutorial misconduct, leading to his full exoneration.

Evidence

Sean Ellis, wrongly convicted of murder in 1993, is finally fully exonerated (The Guardian)

corroborated: 2 independent passages support this claim
XREF: connects to: Ellis’s apparent stumble was mischaracterized by the prosecution. — Lynley Hood, A City Possessed, 2868; Sean Ellis’s conviction was marred by corruption and was later overturned. — Corruption Marred The Investigation of Murdered Policeman: The Case of Sean Ellis; Rollins said the case was ‘tainted by significant and egregious police corruption and prosecutorial misconduct.’ — Judge Overturns Last Remaining Conviction Against Sean Ellis (+1 more)

Rollins said the case was ‘tainted by significant and egregious police corruption and prosecutorial misconduct.’ (similarity 0.94)
Sean Ellis’s conviction was marred by corruption and was later overturned. (similarity 0.93)
Suffolk County DA Rachael Rollins’ office filed a nolle prosequi, officially dropping the charges and fully exonerating Sean Ellis. (similarity 0.87)
Judge Ball overturned Ellis’s convictions ruling that due to police corruption and prosecutors’ misconduct, ‘justice was not done.’ (similarity 0.83)
A judge threw out the remaining gun conviction against Ellis, who spent more than 20 years in prison for the killing of a police detective. (similarity 0.83)
Acting Suffolk County DA John Pappas announced his office would not retry Ellis, citing involvement of three corrupt officers and passage of time. (similarity 0.80)