People are like this, if it doesn't concern them, they remain indifferent, but once it involves their own interests, even the best of friends will think of themselves first.
If it was just a charge of perjury, with the results she found, at most she'd face detention. This method works very well for ordinary people; even if they don't consider themselves, they think of their next generation. But for some people, it doesn't pose any deterrent.
Because they already have criminal records, adding another charge doesn't make much difference.
You don't often see these kinds of people in everyday life, but in police stations, there are plenty, and some even frequent the stations.
And Jiang Jiayan was obviously one of them. She wasn't particularly afraid of detention, but if it turned into a charge of extortion, then it would be a big deal. That charge is often seen on TV and is not a small matter.
