Ballistics experts take stand on third day of Rose homicide trial

Feb. 17—EBENSBURG, Pa. — Cambria County assistant district attorneys called court-recognized ballistic experts to take the stand on Friday to discuss items found in Jaydin Sanderson's vehicle during her 2022 death investigation as well as a pistol Qwante N. Rose allegedly had in his vehicle during a separate incident that year.

The experts provided testimony about the 9mm Canik pistol that had the barrel replaced with another containing an altered serial number but ballistically matched a bullet casing in Sanderson's vehicle but not the bullet that allegedly killed her that was also found in her car.

Rose is accused in Sanderson's shooting death on New Year's Day after the pair attended a New Year's Eve party together — they were allegedly in an on-and-off relationship — and has been charged with criminal homicide and related counts.

Pennsylvania State Police Cpl. Matthew Pergar was the first to testify, and for his part, the prosecution had him discuss the casing.

Cambria County Assistant District Attorney Joseph Green performed the questioning, providing Pergar with the alleged weapon to inspect.

"Trooper, if you're testing a part of a shell casing that was discharged ... what do you do?" Green said.

Pergar, who works in the Greensburg office of the PSP Bureau of Forensic Services, said he would discharge the firearm into a retrieval tank full of water and compare the test casings against the evidence.

The examiner said he would then inspect the casings for class characteristics — he described these as random imperfections and irregularities imparted on the casing by the gun.

Pergar was asked to do this for the Sanderson case because of a separate March 2022 incident in which Rose is alleged to have been involved and the gun in question was located by authorities.

Reportedly, the ballistics from that incident caused a notice in the National Integrated Ballistic Information Network for the Sanderson case.

Upon inspection, Pergar testified, the casing found in Sanderson's vehicle matched the 9mm Canick pistol police recovered from Rose's vehicle.

He confirmed under cross examination with Rose's attorney, Ralph Karsh, that what matched the test casing and evidence was the breach face mark of the Canik pistol, although there were supporting identifiers as well.

The breach face is the mechanism on a pistol that pulls the casing from the chamber to expel it.

Karsh spent a significant amount of time with Pergar questioning how a 9mm pistol operates, how those firearms are manufactured, what in that process leads to individualized markings from gun to gun, and the science behind ballistics.

He also intensely questioned Pergar about how casings are ejected from a firearm, Pergar's methodology for testing in a laboratory setting and how markings come to be on bullet casings.

At one point, Karsh requested Pergar provide the jury with an in-depth explanation of each part of the Canik that may mark a bullet casing.

He then posited that if pieces of a pistol that make markings could be changed then two casings fired from that gun wouldn't match, which Pergar agreed with.

The attorney then attempted for Pergar to concede two different firearms could leave the same identifying marks on a casing, which Pergar contested wasn't accurate.

During re-direct, Green asked Pergar to confirm that the breach face on the Canik could not be changed, and Pergar said that wasn't possible on this model.

The assistant district attorney then inquired if there was any doubt in his mind that the Canik sitting in front of Pergar fired the casing found in Sanderson's vehicle, and the state police corporal said there wasn't a doubt.

However, Karsh had Pergar admit that there was no way to tell when the casing in Sanderson's vehicle was fired — either the night of her slaying or before.

The next witness was Lehigh County Detective Mark Garrett, another firearms and tool- marking examiner, who spoke to the bullet fragment found in Sanderson's vehicle as well as the fact that the barrel on the Canik had been swapped at some point.

Garrett said his testing showed the bullets he fired with the 9mm handgun did not match the bullet found in Sanderson's vehicle that has been confirmed to have her DNA on it — the lands and grooves, or rifling pattern, wasn't the same.

His test fires did match each other, ruling out any defect of the gun causing the issue.

When he inspected the pistol, Garrett determined the serial number of the barrel — which includes the rifling — had been obliterated and when he attempted to retrieve it through a process of sanding and acid etching, he noticed the sequence of numbers didn't match the serial number on the body of the firearm.

"Somebody took a drill and attempted to deface the serial number," Garrett said.

He demonstrated how easy it is to remove the barrel of a pistol as well.

Green asked how the casing can match the gun but the bullet does not.

"This barrel was not part of the firearm at the time of the shooting," Garrett said.

While cross-examining him, Karsh inquired about the lands and grooves of rifling, asked if the rifling of a firearm may alter in such a way to change the pattern if fired at two different times of a year and the bullet fragment found at the scene.

Garrett informed him that rifling can shift but not in such a significant way to be different during the same year and admitted that he couldn't say when the barrel of the Canik was changed.

The last witness the jury heard from was Dr. Manjunath Heggere, an independent contractor pathologist for ForensicDx in Windber who performed Sanderson's autopsy.

He explained to the group the protocols of an autopsy and that the bullet wound that killed the 19-year-old caused a "keyhole" injury.

That means the bullet hit Sanderson's skull at the back, fragmented and entered her head where it destroyed the right side of her brain.

"This was actually an interesting case," Heggere said.

Other details he testified to were that the "keyhole" injury was likely due to the angle of the bullet and that the shot was fired at a distance of more than two feet.

Karsh inquired how long Sanderson might have remained alive after being shot, asking if it were possible she grasped at her head — explaining her blood and hair in her hand — and opened the vehicle door.

Heggere said it is possible she was alive for less than five minutes after being shot and that she may have moved, but noted these questions were hypothetical.

The trial was continued to Monday.