Jane appreciated he was politely saying he didn’t want to risk her missing a bullet hole or indentation in one of the cars. They started on the left-hand side and found nothing on, or under, the cars they looked at. They were having the same result on the opposite side of the road until they reached a silver two-door Ford Fiesta hatchback parked nearest to the crash site. Dabs pointed to the tarmac by the front of the vehicle.

‘See the pool of water there . . . ? You notice anything unusual about it?’

Jane thought his remark odd.

‘No. What’s unusual about a pool of water after it’s been raining?’

‘It’s a rusty brown colour, like you sometimes get from a leaky car radiator.’

She realised what he was thinking. ‘And if something’s leaking it must have a hole in it.’

‘Exactly, and in this case the hole might have been caused by a bullet.’

He put on some latex gloves, then took a picture of the Fiesta with the camera he was still carrying over his shoulder.

Jane looked closely at the front of the car.

‘I can’t see a bullet hole anywhere.’

He crouched down and put his right index finger between two of the grille slats.

‘That’s because these are wide enough apart for a bullet to pass between without hitting the grille.’ He crouched further and looked under the car. ‘There it is.’ He held the camera at ground level and took some photographs.

Jane crouched down and could see a small cylindrical silver object, which she realised must be a bullet.

‘Looks like it lost velocity when it passed through the radiator, then it hit the engine block and fell to the floor.’

He got on his hands and knees and started to lower himself to the road to get to the bullet.

‘You’ll get your clothes dirty – shall I look for a stick or something to get it out with?’

He didn’t stop what he was doing as he lay on the road and reached under the car.

‘No, we never do that, or use tweezers to pick up bullets. The last thing you want to do is mark or damage them in any way.’ He picked up the bullet, then stood up and showed it to her. ‘Although it’s squashed a bit at the top it’s in reasonable condition.’ He held the bullet flat in the palm of his hand. ‘There’s marks on it left by the rifling inside the barrel of the gun.’

He pointed to some tiny linear marks and asked Jane to put on some latex gloves and hold the bullet, so he could take some close-up photographs of it.

Jane thought they looked like scratches and asked him what he meant by rifling.