The defense for a Colorado man accused of shooting a 17-year-old in the face last September plans to put the onus on the weapon used.

"He's absolutely sorry for what happened. It was a complete mistake. It was an unintentional firing of his weapon," said defense attorney David Jones. Jones and co-counsel Chris Decker plan to make the case that the weapon used by Brent Metz in a shooting along Pleasant Park Road in Conifer was faulty and misfired. The teen survived.

"The facts as we understand them are he was drawing it from his truck to place it on his hip, as he was turning, the weapon went off," said Decker.

Metz is very familiar with weapons and regularly carries, said the attorneys.

"He's been a concealed weapon carrying permit for 18 years, he's got extensive experience with firearms," said Jones.

The defense blames the functioning of the Sig Sauer P320 that Metz used.

"There are a number of circumstances well documented where these weapons are going off without the intent or physical interaction of the person holding it," said Decker. "Should there be responsibility? Absolutely. And we feel that should fall on Sig Sauer."

There have been claims from some police officers that weapons have fired while holstered. In February, a federal judge in Georgia denied Sig Sauer's request for a new trial after a Georgia man was awarded $2.3 million after one of the P320s fired as he was holstering it.

Sig Sauer did not reply to a request for comment on the allegations by Metz's attorneys. But last year, it did post a public statement about claims involving the P320.

"Claims that the P320 is capable of firing without a trigger pull are without merit and have been soundly rejected as a matter of law."

Still, the company did offer a free update on the weapon in 2017 and redesigned some internal parts, including the sear, a part that holds back the striker until proper pressure is applied to the trigger.  Metz's gun was produced after the change, admitted Decker.

"Which we believe does not and did not solve the problem here," he said.

Some police departments, including Denver, do not allow the use of the weapon.

"The Denver Police Department Firearm Unit evaluated the Sig Sauer P320 platform and were able to recreate safety issues, which ultimately led the department to make what we believe to be a prudent decision to disallow DPD officers' use of this firearm platform," said DPD in reply to an emailed inquiry.

The Jefferson County Sheriff's Office, the arresting agency in the Metz case, says its use of the P320 is under review. Deputies buy their own weapons, and about 8% use the P320. "We have had zero problems," said department spokesperson Jacki Kelley.

Metz, a town councilmember in Mountain View who is on leave after his arrest, faces a recall election next week.

Whether the gun was faulty or not may not be the core issue of the case. The defense still has significant challenges, even if it claims the gun was faulty, says former prosecution attorney Raj Chohan.

"Very likely the prosecution is going to say that's a bunch of nonsense, given all the context in place: pulling the vehicle in to block the other car from leaving, getting out, pointing the gun in the direction of the person who was shot, and then having the gun go off," said Cohan.

Metz reportedly pulled his vehicle in front of the victim's car at an angle and got out, grabbing a gun off the seat.

The affidavit shows the other teenager in the car told the arriving deputy that Metz got out and walked toward their car. He "pulled a handgun from his holster and pointed it towards them," the teenager said, before it went off, firing a bullet through the windshield and into his companion's face. The 15-year-old said he heard Metz exclaim, "Oh _____, my gun went off."

The defense says they will make the case that he was mistaken about the gun being pointed towards them.

"We don't believe that's the case," said Jones.

Among the gun safety rules published by the National Rifle Association, the first states, "Always keep the gun pointed in a safe direction. This is the primary rule of gun safety." At some point, the gun was pointed toward the victim to fire in that direction.

Chohan believes the defense will have to put Metz on the stand to testify his version of events, which will open him to cross-examination.

He said, "The question is going to be, why did you pull the gun to begin with? And if you didn't mean to use it, why was it out? And why did you block the car in?"

The jury will have to weigh the motivation behind Metz's claims and any conflict with other testimony, particularly from the boys.

"There's going to be some deference given to what they saw and what they remember. And the person who's got the most self-serving version of this is going to be the shooter," said Chohan.

But he added that the defense is doing its job, going after the issue of intent, which is important for the most serious charge of assault in the second degree. The district attorney in Jefferson County had no comment, noting the case is pending.

The next court date is in late June, and the trial will be beyond that. It will be up a judge or jury to decide the validity of the defense's arguments.

"They're going to sit there and go, what makes more sense?" said Chohan.