I have a legal question.

There was a young mother that went missing in a county south of Louisville a few years ago, maybe 2015 or so.  Her car was found with her purse and cell phone inside.  She has never been found.

A past boyfriend and father of one of her many children has been the suspect from the onset.  He is a former LEO that turned to home building.  The FBI has searched everywhere this guy has ever been known to be.  They have excavated driveways and patios of homes he built, excavated areas of his family farm, etc.  No body or weapon has ever been recovered.

This guy was arrested a few weeks ago and charged with her murder.  Now, he seems guilty, but that's not how our legal system works.  My question is that if no body has been recovered, how can someone be charged with her murder?  It's not like it was witnessed that she was pushed off a boat or cliff and the body has not been found.  No weapon has been recovered and not, to my knowledge, DNA evidence.

Maybe she doesn't want to be found?  Maybe she is in another state or country living under a false ID?