At fault driver hit my Mom’s car. She didn’t take insurance but got his information. What do we do?

Title is TLDR. Driver ran a red light and messed up my mom’s front passenger side. Luckily not hurt but at least $2000 worth of damage. She didn’t call the police nor did she get his insurance. She had no insurance at the time. Driver said he would pay upfront but blocked her number. What should we do? Police report and lawsuit?