In the trial of a man accused of bombing a Minnesota mosque, FBI forensic scientists testified that some evidence found at the crime scene didn’t conclusively match defendant Michael Hari.

Ending a second week of testimony in St. Paul’s federal courthouse, Hari’s defense team called its first witnesses Thursday morning, in a strategy to cast doubt on Hari’s involvement in the 2017 attack.

Sherri Fentress, a DNA examiner for the FBI, said a hair found at the crime scene didn’t match Hari’s, per her analysis. Jacqueline Slebrch, another FBI scientist, said some finger and palm prints she analyzed from the scene either didn’t match Hari or were not suitable for reliable analysis.

Hari, 49, of Clarence, Ill., has pleaded not guilty to five federal charges, including civil rights and hate crimes, related to the bombing of Dar Al-Farooq mosque in Bloomington on Aug. 5, 2017.

When the bomb ignited, several members had gathered inside for a dawn prayer. No one was injured, but prosecutors say Hari and his accomplices succeeded in their goal, motivated by prejudice, of traumatizing the Muslim community.

Michael McWhorter, 31, and Joe Morris, 25, have both testified to helping Hari bomb the mosque. Both men said Hari planned the attack, but Hari remained in the vehicle as a lookout while they carried out his orders.

McWhorter and Morris told jurors Hari hired them for an unspecified job, and then picked them both up on Aug. 4 in a rented pickup truck loaded with assault rifles, tactical gear and a homemade bomb. McWhorter and Morris said they had not met until that day, and that Hari only revealed their mission to bomb the mosque after driving through the night from Illinois to an hour outside Bloomington.

When they arrived, at Hari’s instruction, Morris broke open a mosque window with a sledgehammer and threw in a bottle of gas and diesel fuel, according to Morris and McWhorter’s testimony. McWhorter then tossed in the homemade black powder bomb, according to their testimony. The men told jurors they later joined Hari’s anti-government militia, White Rabbits, and, among other objectives, attempted to blow up a clinic that performed abortions in Champaign, Ill.

McWhorter and Morris have both pleaded guilty. They face up to 35 years in prison. Both say they hope they will receive lower sentences for their assistance with the prosecution of Hari.

In opening statements, Hari’s attorney, James Becker, instructed jurors to watch testimony with a skeptical eye as to whether prosecutors prove beyond the standard of a reasonable doubt that Hari took part in the bombing.

The trial is in recess Friday and will resume Monday. Closing arguments are expected to take place next week, after which the case will go to the jury.