Bexleyheath and Eltham News Shopper, February 23, 2018
You generally put quotes in a heading to indicate that the content is an allegation or claim in an attempt to deflect a lawsuit or having to put in apology. (Beware: it does not always work). For example:
Obviously an inanimate object such as a thermostat can’t sue so quotes are unnecessary. You don’t need to put them round ‘harmless’ either.
In the intro, it would have been good to put suspicious rather than suspicions (without quotes). Still, it’s near enough, so who cares?