Redondo Beach city prosecutor Brenda Wells did not disclose details of the plea deal.
Haddad worked at Redondo Union High School as a media arts teacher. His sentencing is scheduled for Oct. 20.
The 50-year-old was arrested on Dec. 3, and since then, two other girls have come forward to report similar incidents.
Haddad faces trial for three misdemeanor counts of annoying or molesting a child and a single count of indecent exposure.
The Associated Press contributed to this report.
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