In House M.D., what is the name of the private investigator hired by Dr. House?

In House M.D., Dr. House hires the private investigator Lucas Douglas.

Lucas is introduced in the fifth season as a private investigator whom House employs to gather information about patients and other people. His unconventional job gives him access to records, personal histories, and observations that House can use when ordinary medical questioning is insufficient.

The character is played by Michael Weston. Lucas’s role reflects one of the show’s recurring ideas: House is willing to use unusual methods when pursuing an explanation for a patient’s illness. His investigative work also expands the series beyond the hospital’s normal medical staff.

Lucas should not be confused with Michael Tritter, a police detective whose conflict with House forms a separate fifth-season storyline. Lucas is a private investigator, not a law-enforcement officer.