SANDPOINT — A defense expert testified Monday that measurements and bullet trajectory conclusions drawn during Elvin “Eli” Holt’s autopsy are anything but exact.

“There’s always a certain amount of uncertainty,” Dr. Kenneth Mueller told jurors during the fifth day of James Matthew Anderson’s second-degree murder trial. “There’s always some doubt on the periphery.”

Although Mueller, a Harvard-educated pathologist, said there was little doubt the autopsy of Holt was properly conducted, he emphasized that some of the conclusions made by Dr. Sally Aiken should be considered as approximations instead of unequivocal facts.

Aiken, a medical examiner for Spokane County, Wash., testified last week as a state’s witness. She told jurors Holt died of a loose-contact gunshot wound, meaning the barrel of Anderson’s .44-caliber pistol was likely touching Holt’s face when the weapon discharged.

Aiken also testified the trajectory of the bullet was downward, about 20 degrees off horizontal.

But Mueller pointed the precise trajectory cannot be known because of unknown variables such as the exact position of Holt’s head when he was struck by the gunshot. Mueller said the trajectory was likely between zero and 20 degrees off horizontal.

“It’s very difficult to say if it was exactly 20 degrees off horizontal,” said Mueller.

Mueller also testified that a firm conclusion could not be drawn that the muzzle of the revolver was touching Holt’s face because of the catastrophic dynamics of a high-powered gunshot fired at close range.

Chief Public Defender Isabella Robertson opened the defense case on Friday by calling Anderson’s orthopedic surgeon, a Bonner County Jail deputy and a witness who saw Holt and his stepbrother in the hours leading up to the shooting.

Anderson, who is invoking his right to remain silent at trial, told investigators he was physically confronted by Holt and Freir, both of whom had been drinking, outside his trailer in Sagle in the waning hours of Thanksgiving 2008. Anderson alleged threats were made  his family, prompting him to obtain the weapon and convince the unannounced, late-night visitors to leave.

Anderson contends the cocked weapon discharged accidentally when he leveled it.

The Kootenai County doctor told the jury Anderson was recovering from knee surgery when the shooting happened. The witness, William Ross, told jurors Freir appeared to be “agitated” and “frustrated” before the shooting took place.

The jailer, meanwhile, testified of photos he took when Anderson was booked into the facility the morning after the shooting.

The defense’s booking photos showed what appeared to be a blackened eye and distinct red marks on Anderson’s throat. The state’s booking photos show fainter red marks and no black eye.

The state argued on Monday that the red marks on Anderson’s outstretched neck were merely natural skin creases that formed when the defendant’s neck is in a relaxed, forward-looking position.

Both sides profess to having copies of the original images that were taken when Anderson was booked.

The defense rested on Monday, clearing the way for jury instructions and closing remarks today.