Fraudulent Billing, health and medical assignment

I need help with a Health & Medical question. All explanations and answers will be used to help me learn.

Dr. Pearson has recently been hired into the Central City Internal Medicine Group as its fifth physician. He has recently completed his residency and is eager to enter private practice. Dr. Pearson is introduced to Meredith and Dawn, two members of the billing staff for the practice. Unbeknownst to Dr. Pearson, Meredith financially assists the practice in several ways. She bills procedures by using individual codes instead of comprehensive codes, she has decided to bill Dr. Pearson’s services under the Medicare number of Dr. Craig (another Central City physician) until Dr. Pearson’s credentialing process has been completed, and habitually submits a claim more than once if she isn’t sure whether or not it has already been submitted.

Name the types of fraudulent billing that Meredith is conducting. (Name the specific Act)
Could Meredith be held liable for these activities?
Is Dr. Pearson subject to liability although he doesn’t know Meredith is conducting these activities? (Is Dr. Pearson responsible for the behavior of his staff?)
Once Meredith’s activities are discovered, how should her conduct be addressed by her employer, Central City Internal Medicine? (What action might her supervisor take against Meredith? Consider what she learned as a new employee)
What should Central City do to ensure these types of problems don’t occur in the future? (Look at it from a perspective of new hires. What should be done so they know this type of action is wrong?)