Can I have my committee submit their scores and lock the score so they cannot change it the score for each applicant they review?

Yes, this is a setting you can turn on. Only Global Admins can toggle this option from the Admin Dashboard. > Click the "Administration" section. > then Click the "Site Settings" icon.

Under the Reviewer Screen Settings header there is a radio button called "Enable Submit Functionality for Reviewers" check yes.

NOTE: This activates the ability for reviewers to do a final submission of their scores, once they have completed scoring an applicant. Once the reviewer submits the score on an applicant they cannot go back in and make changes to their score unless you release the applicant's scorecard back to them.