Court admissible evidence is more likely to turn up when it's front page news and people are digging though.
Same with the recent story about a famous pub called the Crooked House, which mysteriously caught fire a month after a new owner took over the closed premises and was demolished remarkably swiftly. Because it generated a lot of outrage (not from regular patrons, but from people who liked how it looked), it got more attention than your average arson where the owners were obvious suspects, and sure enough there have been actual arrests as well as rumours about other fires involving the same owners and evidence of demolition equipment having been leased the day before the fire