He was arrested for failure to disclose payments from China, which is actually a growing prosecution area for DOJ generally in light of China's Thousand Talents initiative. This is not a unique prosecution. Besides, the conduct he was charged for occurred in 2018 and 2019.

The bigger question is if the guy sold a deadly virus to China and was arrested by DOJ in January for doing so, then why on earth would the current administration wait until mid-March to take COVID-19 seriously? The timeline does not add up in any way.

Link to DOJ's release: https://www.justice.gov/opa/pr/harvard-university-professor-and-two-chinese-nationals-charged-three-separate-china-related