tl;dr: Old dealers and drug users told the Globe that from high school to age 22, Doug dealt a lot of drugs to other drug dealers. The police in his area said they had no recollection of anything to do with any of the Fords and drugs, including the officer that arrested Randy Ford (Rob and Doug’s other brother) for putting someone in a trunk and kidnapping them to shake the kidnapee’s parents down for drug money. Snippit:

As a dealer, Doug Ford was not highly visible. Another source, "Tom," who also supplied street-level dealers and has a long criminal record, said his girlfriend at the time would complain, whenever he was arrested, that he needed to be more calculating "like Doug." [...] When asked where Mr. Ford fit in the hierarchy of dealers in their neighbourhood, [another interviewee] replied: "He'd be at the top."