It's certainly possible provided there is enough evidence to prove the offense. Btw, do not post anymore details anywhere on the Internet. From your summary two important factors are not sufficiently fleshed out. If the store employee observed the crime being committed then the issue of establishing the crime is satisfied by that person's evidence. If the license plate leads to a suspect and that suspect is positively identified by store personnel or by security video footage then the final piece of the puzzle is in place. If police go to the car owner's home an interview him, there is a good chance that person will make the cardinal mistake of making the case against him rock solid.
An employee's suspicion of shoplifting does not rise to the requisite level of Probable Cause to make an arrest or proceed with prosecution if it is a mere hunch. However, if this suspicion is based upon the employee's first hand observation of the crime taking place then yes, probable cause to arrest and prosecute exists. It would have to be a citizens arrest unless this were felony grand theft, but the citizens arrest really boils down to an affidavit signed by the employee and the cops do all the dirty work. That said, the information discovered from the license plate number would need to corroborate the employee's story and they would likely need to identify the suspect or the suspect could be identified via security video footage.
So, the short answer is yes. If they have one credible witness and there is no need to actually find the merchandise on the suspect or connect them to it in order to bring charges against the suspected thief. That doesn't mean they'll prevail on those charges, but they can bring them.
Don't spread anymore facts of your case online. Talk to a local attorney as soon as you can. I offer free consultations and would be happy to discuss this case with you.