Lawyers for Dylann Roof, the suspect in the shooting and killing of nine people inside the Emanuel AME Church in Charleston, South Carolina in June last year, are challenging the federal hate crimes law which their client has been accused of breaking even as they seek to convince prosecutors not to pursue the death penalty.

Roof's defence team said the hate crimes stature "affords the federal government virtually unchecked discretion to prosecute crimes already being punished by the states," the Associated Press reports.

The 22-year-old suspect is facing 33 federal violations including hate crimes and obstructing the practice of religion. Roof allegedly told a friend that he wanted to start a race war.

His lawyers previously said that Roof would plead guilty if death penalty is not included. Prosecutors are given until July 25 to respond.

Roof's federal trial will begin in November and defence lawyers may try to "derail the trial" unless the judge orders that jury members be chosen from a state-wide pool, prosecutors said in a court filing.

"The government requests this Court use a (pool of potential jurors drawn from across South Carolina)," said federal prosecutors, according to The State, adding that the reason is "to ensure that the scheduled trial not be interrupted."

Until recently, the jury was expected to have been chosen from a Lowcounty jury pool, where members would come from Charleston and eight other counties.

Assistant U.S. attorneys Jay Richardson and Nathan Williams told Judge Richard Gergel that Roof's lawyers may try "an 11th-hour attempt" to change the jury pool to a state-wide pool that could delay the trial.

Prosecutors also said defence attorneys might make a last-minute request to change the trial's location from Charleston.

They also said that without a state-wide jury pool, it will be harder to choose "a fair and impartial" jury as "most of the parishioners who were murdered and those who survived Roof's attack ... have strong ties to the Charleston area."

The judge will hold a hearing on July 18 to decide on the location and manner of jury selection.