The journalist was sent to cover a demonstration on the roof of a Suffolk County Council building. The man cannot be named for legal reasons, but it is thought that he was protesting his family's treatment by social workers.
The 38-year-old man climbed on the roof at 4.20am, according to the Ipswich Star, but was coaxed down around five hours later after Furniss promised him an interview in the paper.
Police had set up a cordon around St Edmund House in Rope Walk at 6am, and staff at the building had to enter around the rear.
Furniss noted that the man appeared to be ready to stay on the roof for a long period of time as he had "a flask of tea, sandwiches and a sleeping bag". He had also unfurled a banner saying "STOP DESTROYING FAMILYS" (sic).
Police negotiators had tried and failed to persuade him down, and so Furniss suggested that he extend the offer of an interview to allow the man to discuss his grievances.
"It seemed to work," Furniss said.
After giving his account to the Ipswich Star reporter, the man was then taken into custody by police.
He was later charged with using threatening words and behaviour to cause harassment, alarm or distress. He has been bailed ahead of a court appearance on May 14.
A Suffolk Constabulary spokesman said: "Police were called at just before 6am this morning with a report that a man was protesting from a rooftop in Rope Walk in Ipswich.
"Officers attended and an area around Rope Walk, either side of St Edmund House, was cordoned off to pedestrians. The incident ended peacefully at 8.55am."