Snow-free roof leads police to marijuana farm

HAARLEM, Netherlands, Feb. 12 (UPI) -- Netherlands police said they were tipped off to an illegal marijuana farm when the heat from the resident's lamps melted the snow on the roof.

Police tweeted a photo from the Feb. 5 raid in Haarlem, showing how neighboring homes were covered in snow while the roof of the home that concealed the marijuana plants was bare from the heat of the lamps used to nurture the plants.

Investigators said the same method was used recently to root out pot farms in Zutphen, Arnhem and Amersfoort.

"No snow on the neighbors' roof? You can report suspected cannabis farms anonymously," police said in the tweet bearing the picture of the Haarlem roof.

Cultivation of marijuana is legal in the Netherlands, but the law limits residents to five plants per home.