A key witness in an attempted murder case was at his wits' end by the time he returned to Madley's General Store in Haines Junction, driving a damaged RCMP crew cab.

Deputy conservation officer Shane Oakley had already dropped off the injured and bloodied Cpl. Kim MacKellar at the nursing station.

He'd done so following a high-speed chase during which MacKellar was injured while driving when "gunshots” were fired.

There was a hole in the driver's side of the windshield of the police truck. Oakley had described it as a bullet hole, the nine women and five men of the Yukon Supreme Court jury have heard so far this week.

Christopher Cornell, 31, of Whitehorse, is facing charges of attempting to murder Oakley and the corporal by shooting at them during the chase along the Alaska Highway early on Sept. 26, 2011.

He's also charged with assaulting the custodian at Madley's by spraying him with bear spray, and using violence against the custodian while robbing or attempting to rob the general store.

Cornell also stands charged with using a rifle while fleeing the scene of a robbery or attempted robbery, as well as shooting at a marked RCMP vehicle.

The trial is scheduled to last three or four weeks.

Jessica Johnson, a 22-year-old Whitehorse woman, is facing the same charges but is not on trial at this time.

Under cross-examination by defence lawyer David Tarnow, Oakley testified Thursday that he doesn't remember what happened to the bullet casing he was shown by somebody who had picked it off the ground in front of Madley's.

The deputy CO testified he remembers it was a casing for a .375 H & H rifle. Whether somebody actually placed it in his hand, and what he did with it had it been given to him, he said he does not remember.

"At the time, I was maxed-out,” he said of his stress level.

Tarnow had Oakley review photographs taken of the police vehicle during the investigation, showing a bullet casing inside the cab.

He asked about his knowledge of preserving a crime scene, given his job as a deputy CO.

In his role as a deputy CO, Oakley said, he doesn't do much investigating, dealing mostly with problem wildlife.

The defence lawyer told Oakley he still must understand the importance of preserving a crime scene.

Oakley acknowledged he knows of that importance.

Tarnow said the RCMP truck he was driving when he pulled into Madley's was essentially a crime scene, and Oakley agreed.

But he said preserving the crime scene was not on his mind at all when he was at Madley's following the hair-raising highway chase.

"I was at my wits' end,” he testified.

Tarnow insisted in his loudest and most direct voice so far this week that Oakley would not have removed a bullet casing from the crime scene at Madley's and placed it in the police vehicle.

"You did not do that,” he said, tapping his finger noticeably on his note pad, as if to emphasize his point. "You would not do that.”

"I can't say what I did,” Oakley replied.

He was the second witness called by Crown prosecutor Keith Parkkari. Madley's custodian, Frank Parent, was the first.

Parent testified he'd arrived at the store sometime before 7 a.m.

He told how he noticed an individual in the store while he was almost finished the sweeping.

He approached the individual and grabbed them from behind. He saw a second person from the corner of his eye.

Then he was punched in the nose, hard enough to break it. He heard a male say, "Grab the bear spray.”

When he opened his eyes, there was yellow mist over his face, and his eyes and face were burning. The individuals had left the store, Parent testified.

Having trouble seeing, it took him three times to dial the right number for the RCMP.

He testified when he went to the front door of the store, he was surprised to see the two individuals still outside, trying to load the store's safe into the back of a vehicle with a pallet jack.

Parent said he stayed inside, not wanting another confrontation.

The deputy conservation officer said he was awakened at 6:12 a.m. by the phone ringing. A neighbour in the Willow Acre country residential subdivision left a message that two people were breaking into her house.

Still in his pajamas, Oakley put on boots, threw on his CO jacket and walked out to the road to see if he could see anything. He heard Cpl. MacKellar start his truck, as MacKellar lives right across the street.

MacKellar left toward town but returned quickly. Oakley stepped onto the road and asked MacKellar if he needed a hand, as the COs and RCMP often work together.

While driving to the firebreak around the subdivision to see if they could see anything, they received a call on the police radio about a break-in occurring at Madley's General Store.

When they arrived, they saw a black SUV-type vehicle parked in front, next to the custodian's truck, the jury heard.

Oakley testified it was still dark, but with the headlights, he could see a man in the driver's seat and a woman in the passenger's seat, though he could not see their faces.

MacKellar pulled up to the SUV. As he was getting out, the vehicle backed up into the guard rail, then sped forward between the RCMP crew cab and Parent's truck.

It headed north along the Alaska Highway toward Destruction Bay, with MacKellar and Oakley giving chase.

Soon into the pursuit, the black SUV began driving in the opposite lane. Things started flying out the rear passenger door – a generator, numerous power tools, a hind quarter of deer meat, emergency highway markers.

At one point, Oakley said, he saw the rear window of the SUV shatter or blow out, with a man inside falling backward.

The deputy CO told the jury that shortly after that, as they passed a vehicle parked on the side of the road, he heard a noise, and the dashboard inside the RCMP crew cab exploded.

When he looked at MacKellar, blood was beginning to pour down his face, and the officer pulled the truck over.

Oakley assisted him to the passenger seat, and drove back to Haines Junction. The driver's side window was gone, he told the jury.

The defence lawyer reminded Oakley of his statement to the police.

Oakley had said in the statement that because of the timing of events, there must have been two groups that morning – one at his neighbour's, who left the message, the other at Madley's.

Oakley acknowledged under questioning that he and MacKellar never did check out the neighbour's, though there was no explanation why.

The defence lawyer also reminded Oakley that in his statement to police, he'd said the vehicle they saw parked on the side of the road may have been following them during the chase.

Oakley said that's what he'd said that day, but he told the jury Thursday the SUV they passed parked on the side of the highway could not have followed them.

The defence lawyer asked if the parked SUV had passed them on the highway that morning.

Oakley said it definitely did not, and that he and MacKellar had never lost sight of the black SUV they were chasing.

The defence lawyer asked Oakley if he was certain the loud noise he heard before the explosion of glass inside the cab occurred as they were passing the vehicle parked on the side of the road. Oakley said he was certain.

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