A member of Los Angeles Mayor Antonio Villaraigosa's staff told police that she and city commissioner Andrea Alarcon were at a downtown hotel on the night Alarcon's 11-year-old daughter was found unattended at City Hall, sources told The Times.

Lorraine Green, an assistant to a top Villaraigosa aide, was the first to make contact with police officers as they searched past midnight for Alarcon, who is president of the city's Board of Public Works, according to law enforcement sources familiar with the Nov. 16 incident. The sources requested anonymity because an investigation is continuing.

The Times reported last week that Alarcon, 33, was the subject of a child endangerment inquiry. She has since announced she is seeking professional treatment; she did not specify what type.

Green, 42, is not a subject of the investigation but may be a witness, the sources said. Green did not comment on the matter when reached Thursday. Villaraigosa spokesman Peter Sanders said only that the mayor was not with Alarcon that night "at any time after he left City Hall," where he was honored at a gala thrown by Project Restore, a group that renovates city landmarks.

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