An 85-year-old Idaho mother who shot and killed a home intruder committed a "justifiable homicide" that is "one of the most heroic acts of self-preservation I have heard of," Bingham County Prosecuting Attorney Ryan Jolley stated in an incident review.

The suspect, identified as 39-year-old Derek Condon, entered the home Christine Jenneiahn shares with her disabled son around 2 a.m. March 13. Condon was "dressed in a military jacket, black ski mask, and pointing a gun and flashlight" at Jenneiahn, according to the document.

Jolley says Condon placed Jenneiahn in handcuffs and took her into the living room of her home, where he took her at gunpoint and handcuffed her to a wooden chair.

After demanding to know where the valuables were kept in the home, Condon allegedly placed his pistol on the victim's head when she told him she did not have much. Jenneiahn then told the home intruder about two safes downstairs, and the prosecutor says he left her handcuffed in the living room while he went to rummage through the home.

COLORADO SCHOOL BUS AIDE CAUGHT ON CAMERA STRIKING NONVERBAL AUTISTIC BOY: POLICE

Condon reportedly became angry when he found out Jenneiahn's son was in the home, and she did not tell him. The suspect is said to have made numerous threats to kill Jenneiahn. 

"At one point while Condon was downstairs, Christine drug the chair she was handcuffed to into her bedroom, and retrieved her 357 magnum revolver from under her pillow," Jolley wrote. "She then went back into the living room and hid the revolver between the arm rest and cushion of a couch next to where she was seated and waited to see what Condon did next."

SUSPECT ARRESTED AFTER YOUNG MOTHER STABBED TO DEATH WHILE WALKING WITH HER BABY

The victim's memory "remains somewhat unclear" as to what happened next, the prosecutor's statement says, but at some point, she made the decision that it was "now or never," drew her gun and struck Condon with two shots. 

"Condon returned fire emptied a 9mm pistol into Christine striking her multiple times in her abdomen, leg, arm and chest," the document states. "Condon then went into the adjoining kitchen where he died from his wounds."

Jenneiahn fell to the floor while still handcuffed, and was there for about 10 hours before her son found her and gave her a phone to call 911. Deputies arrived at approximately 12:17 p.m. and provided lifesaving measures. 

Investigators found a broken rear window at the home and a screwdriver near the door where Condon had entered. His car was also found near the home, with footprints going from the vehicle toward the residence.

"Condon had on his person a lock pick set, his car key, a handcuff key, and a bag containing items he had stolen from the residence," Jolley said in the case review.

He said the case "presents an easy analysis of self-defense and justifiable homicide," adding that Jenneiahn's "grit, determination and will to live appear to be what saved her that night."

Had Condon survived, Jolley said he would have charged him with multiple felonies, including attempted murder, kidnapping, burglary, aggravated battery and grand theft.