Would a company investigate a complaint from someone that doesn’t work there?

Let’s say a man named Bob works at Company A. Years ago, he bullied, stalked, and harassed a young woman named Jane at college.

10 years later, while he is working at Company A, Jane (who doesn’t work at Company A) finds out where he works. She contacts Company A to report what Bob did to her in college.

Would HR investigate this complaint if Jane isn’t employed at Company A? Could Bob be fired or at least get in trouble? Would HR ignore Jane’s complaint?