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

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

Lucas Douglas is portrayed by Michael Weston. House hires him during the show’s fifth season, initially using him to investigate people and gather information that House could not easily obtain through ordinary hospital channels.

Lucas is observant, unconventional, and comfortable operating outside formal medical procedures. His work gives House a way to pursue personal investigations, including background checks and surveillance, while also creating a different kind of partnership from House’s relationships with doctors.

Lucas later becomes involved with House’s wider circle and is connected to Cuddy’s storyline. Viewers sometimes confuse him with Michael Tritter, a police detective who becomes House’s adversary in another season. Lucas Douglas is the private investigator; Tritter is the police officer who investigates House after a clinic encounter.