LIVERMORE FALLS — Police began a seventh investigation into a theft of copper from a house within 20 days on Thursday.

An owner of a house on the lower end of Park Street was mowing the lawn and noticed the back door had been damaged, police Chief Ernest Steward Jr. said Thursday.

The forced entry followed the same pattern of the other six homes that have had copper ripped or cut from the plumbing system or furnace, he said.

In this case, it was copper taken from the heating system.

The theft was reported at 9:53 a.m. Thursday. The copper’s value is estimated to be $500.

Police have collected evidence from the scenes of the burglaries and have taken it to be analyzed for DNA.

Other houses that have been hit by copper thieves are on Moose Hill Road and Pleasant, Sewall, Knapp and Wheeler streets.

Jay also had a theft of copper from a house on Belleview Drive within the same time period.

dperry@sunjournal.com