A 'criminal lawyer' ought to mean a lawyer who commits crimes (thankyou Steve!) or should be expressed as a 'criminous lawyer' i.e. a lawyer concerned with crime.
A lawyer is someone who practises law, qualified, licensed or not.
A solicitor is a lawyer qualified and licensed to do various things, like appearing as an advocate in lower courts.
A barrister is a lawyer and advocate licensed and qualified under a different set of rules, who can appear in any court. He can only be hired by a solicitor.
A legal executive is a posh modern name for what used to be called a solicitor's clerk, i.e. someone who does the real work in a solicitor's office while the boss is playing golf.
An attorney is someone you appoint to act in your place. If you appoint him to act for you in legal matters he is an attorney-at-law.
I trust that makes it all much more confusing!