A former Honolulu police lieutenant who is scheduled to begin serving a three-and-a-half-year prison sentence next month in Hawaii’s biggest ever corruption case is asking a judge to let him remain free while he appeals his conviction.

Derek Wayne Hahn’s attorney said Wednesday that the appeal could take several years.

A jury convicted Hahn, another former police officer, a former Honolulu police chief and the ex-chief’s former prosecutor wife of conspiracy in a plot to frame a man.

Hahn helped Louis and Katherine Kealoha, the former chief and the former prosecutor, with the framing of the man to preserve the couple’s lavish lifestyle, prosecutors said.

Hahn is scheduled to surrender at a federal detention center in Oregon on June 1, but his attorney filed the motion Wednesday saying Hahn should remain free until the conclusion of his appeal.

The appeal to the 9th U.S. Circuit Court of Appeals will focus on instructions to jurors before they deliberated and other issues, said Hahn’s motion by Sacramento, California attorney Timothy Warriner.

“Counsel is still reviewing the record and researching possible legal issues, and therefore may file an opening brief in the 9th Circuit that raises claims of error in addition to those stated herein,” the motion said.

Hahn, who has been free on a $50,000 bond since 2017, is not likely to flee or pose a danger, the motion said.

A U.S. judge in Honolulu will consider the request at a hearing on May 25.

Louis Kealoha is scheduled to begin his seven-year sentence June 1. His now estranged wife was sentenced to 13 years in prison.

A judge said she was the mastermind behind the scheme to frame her uncle for the theft of the couple’s home mailbox to hide fraud that included stealing from her own grandmother.