COLUMBIA, S.C. — Charging Dylann Roof’s friend may help prosecutors get him to testify about the alleged Charleston church shooter’s state of mind before nine people were killed.

According to an indictment, Joey Meek knew about Roof’s plans to shoot black church members during Bible study at Emanuel African Methodist Episcopal, didn’t report it and lied to the FBI after the massacre.

Meek, 21, faces federal charges that, if convicted, could land him in prison for years. But with Roof already in jail facing federal hate crime charges and nine state counts of capital murder, why would there be a case against Meek?

Legal experts say prosecutors likely want to show Roof’s alleged acts were premeditated and intentional, which are vital to pursuing a death-penalty case.

“By having a charge against him (Meek), they have more leverage with him to go ahead and make some sort of plea bargain: You testify. You tell us the truth, and we’ll give consideration on the charges or penalty involved,” longtime criminal defense attorney Jack Swerling said.

During a hearing in Columbia on Friday, Meek stood before a federal magistrate in handcuffs, shackles and an orange jumpsuit. He pleaded not guilty and his bond was set at $100,000.

Meek hung out with Roof off and on in the weeks before the June 17 shooting. A day after the shooting, Meek told The Associated Press Roof had drunkenly complained to him that “blacks were taking over the world” and “someone needed to do something about it for the white race.”

Authorities say Meek knew more, writing in the indictment he knowingly lied to an FBI agent when he said “that he did not know specifics of Dylann Roof’s plan to shoot individuals on a Wednesday, during Bible Study, at an AME Church in Charleston, S.C.”