Standing in the middle of a paddock in a remote part of the Catlins, he froze as a spotlight's beam stopped on him.
Heart pounding, he considered his options.
''I didn't know what to do. If I lay down, they may have thought I was a deer. So I turned my headlamp on, the spotlight disappeared, and they drove off.''
The encounter left Mr Lemm and his wife shaken.
Over the past six months, at least four hoggets and three cattle beasts have been shot and left on land leased by Mr Lemm at Florence Hill near Papatowai.
Judging from the marks left, it appeared two of the cattle beasts had fallen off a cliff and on to the beach after being shot, he said.
About a week ago, Mr Lemm heard a calf bellowing but did not see anything untoward.
A few days later, he came across the carcass of a cow.
It had been shot, its throat slit, and hind legs and back steaks removed.
The slaughter left the calf motherless.
The bullet will be removed and handed to police.
A strop (tie-down strap) was found nearby and Mr Lemm believed a quad bike had been used to move the stolen meat.
The shootings left Mr Lemm several thousand dollars out of pocket, angry and frustrated.
He said some of the farmland gave access to prime fishing spots like King's Rock and Rainbow Island.
''It's dangerous, because I also give hunters permission to hunt there ... it's a safety issue. Who is around with firearms? Who knows who is out there?''
It was common to see spotlighting from the roadside, despite it being illegal, he said.
Two nearby farmers had also had deer shot and left on their properties.
Another farmer told him he had issues with people ''continually'' spotlighting in a paddock containing deer, even though there were four houses nearby.
Acting Sergeant Steve Griffiths, of Balclutha, said illegal hunting was an issue across the Southern police district. Not only did it put in jeopardy genuine hunters' chances of legally hunting on farmland, it also put lives at risk.
''These are senseless acts, killing animals for the sheer fun of it. Why would you shoot an animal for fun?''Police planned to increase patrols in the area - during the day, night, or weekend, Acting Sgt Griffiths warned.
Landowners should contact their local police station or, if they were unavailable, the Balclutha station, as soon as possible after seeing suspicious behaviour or slaughtered animals.
Taking down vehicle details - registration number, make and model - would also help police, but people should only do this if it did not put safety at risk.
Offenders could face a range of charges, including illegal hunting, theft of an animal and being unlawfully on property.
