"He came at me, and I fired," James George Stiffler told a 911 dispatcher moments after fatally shooting a man.
Stiffler said the man, Henry Thomas Johnson, ransacked his Helena home then threatened him.
"I caught him breaking into my house," Stiffler said in the recorded call from May 22, 2013.
The call was one of the first items placed into evidence by the prosecution during the first day in testimony for Stiffler's deliberate homicide trial Tuesday in Helena district court.
Stiffler shot Johnson in the back. The alleged intruder fled the home through a window and got into his girlfriend's silver Ford Taurus, where he succumbed to his injuries.
Attorneys in the case agree Stiffler shot and killed Johnson. The circumstances under which he fired the fatal shot are being debated.
The defense says Stiffler feared for his life. Prosecutors allege Stiffler shot a man who was trying to flee.
"He is going to testify that he was frightened by a burglar who literally kicked his door in," Nicole Siefert, one of Stiffler's lawyers, told jurors.
"He was forced to pull out his gun. He was forced to fire," Siefert said.
"Mr. Johnson ultimately caused his own death," she added.
Stiffler knew something was amiss when he saw the strange car parked in his driveway, Siefert said. As Stiffler approached his home, he took his gun out of his briefcase. When he confronted the man he says was burglarizing his Canyon Ferry Road house, Johnson raised his fists and threatened to hurt Stiffler, she said.
"In a split second, Jim makes the decision to pull the trigger," Siefert said.
A medical examiner testified the bullet struck the back of Johnson's eighth rib, went through his left lung and exited through the breastbone.
Prosecutors and investigators say Stiffler's version of the events leading up to the shooting vary and don't mesh with the physical evidence.
When detectives attempted to question Stiffler to clarify consistency issues about a week following the shooting, his attorney at the time, Royal Davis, spoke on his behalf. At the time, Davis voiced more concern about a civil suit from 37-year-old Johnson's family than criminal charges.
Prosecutors played a taped interview with Davis and Stiffler.
"He says he doesn't remember a thing about it," Davis said in the recording. "My guy doesn't remember firing a bullet hole into the guy."
"He has to be very careful what he puts on the record himself," he added.
In the recording from 2013, investigators informed Stiffler prosecutors were contemplating criminal charges.
In her opening arguments, Melissa Broch, deputy county attorney, said the felony deliberate homicide charge was filed in April 2015 after a forensic expert hired by prosecutors determined Johnson was shot while climbing out of a window.
Testimony will continue Wednesday morning. The court has set aside two weeks for the trial.