When Mauricio R. Celis, the majority partner in former Corpus Christi, Texas, firm CGT Law Group International, goes to trial in Corpus Christi today, prosecutors will rely on a little-used law that makes it a crime to impersonate a lawyer for economic benefit.

“A criminal prosecution for holding oneself out as a lawyer is rare,” says Leland de la Garza, a partner in Shackelford, Melton & McKinley in Dallas who chairs the Texas Unauthorized Practice of Law Committee.