The event was organised by Magistrates In The Community, the Citizenship Foundation and the Magistrates Association.
Each team was briefed on the same fictional case and given time to prepare cases for both prosecution and defence.
Adopting roles as lawyers, legal advisors, magistrates and defendants, the students were assessed by a panel of legal professionals.
Durrington High School came out on top after presenting the strongest overall cases and will progress to May’s regional finals.
A national final will take place in June, featuring the brightest of up to 7,000 students across the country.
Susan Pyper, Lord Lieutenant of West Sussex, presented the winning team with a trophy and students took part in a question and answer session with local judges, solicitors and probation workers.
A pair of Worthing’s police dogs made an appearance and students were given tours of the building’s cells and courtrooms.
One participant said: “I was very nervous in the courtroom. I enjoyed it, but it felt more serious than I expected.
“Afterwards, I asked the district judge if he gets nervous in court. He said that he feels that way all the time, which made me feel better.”