ST. LOUIS — Lamar Johnson is serving a life sentence, convicted of killing a man during a drug deal in St. Louis in 1994. His family and legal advocates said he is innocent. Thursday, they gathered outside of Missouri Attorney General Eric Schmitt’s Office in St. Louis, demanding a new trial.

“We grew up without our father,” said Brittany Johnson, Johnson's daughter. “Time has gone by. Everything is coming to the light, and there is no turning back.”

The organization Color of Change said it collected more than 25,000 petition signatures on Johnson’s behalf. Advocates delivered the petitions to staff at Schmitt's office.

“For 25 years, Lamar has languished in jail for a crime he did not commit, waiting to see justice done,” said Marybeth Onyenkwu with Color of Change.

Prosecutors, legal scholars back appeal in Lamar Johnson murder conviction

St. Louis Circuit Attorney Kim Gardner has supported Johnson's request for a new trial. She said misconduct by police and a former St. Louis prosecutor led to Johnson's conviction.

This summer, a judge ruled that Gardner's claims are inconclusive and she doesn't have the authority to grant Johnson a new trial.

READ MORE: Prosecutors, legal scholars back appeal in Lamar Johnson murder conviction

READ MORE: Judge says she can't order new trial for man convicted in 1994 murder

Johnson's supporters said they want the attorney general to grant a new trial.

Schmitt’s Office sent the following statement:

“Put simply, the court asked the Attorney General into this case because it didn’t believe that the Circuit Attorney’s Office followed the correct procedure in filing a late motion for new trial on behalf of Lamar Johnson in the wrong court. Our only involvement at this stage is ensuring the correct procedure is followed and the rule of law is upheld – we’re not here to comment on innocence or guilt. That can be decided by the proper court, in the proper venue, following proper procedure. Mr. Johnson has filed a direct appeal and multiple state and federal habeas corpus petitions over the past few decades, which have been denied. If he has new evidence that he wishes to present, he may file another petition in the proper court and make his case.”