When Fontainebleau High School sophomore Matthew DeCossas was called into school administrators’ offices on Jan. 8, they wanted to know if the 16-year-old had marijuana on him.

They searched his person, his bag and his locker and found nothing. Then they asked for his cellphone.

What they found on the phone started a chain of events that led to DeCossas’ expulsion from school. It has also landed his case in federal court, where school administrators are accused of violating the basic constitutional rights of students.

After not finding any marijuana, administrators took DeCossas’ phone and asked him to unlock it, which he did before returning to class.

Administrators found on the phone a text conversation DeCossas had with another student about getting some Vyvanse, a stimulant used to treat ADHD. They summoned him back to the office and began to interrogate him and the other student separately.

Matthew DeCossas Suit

When it was over, DeCossas had been recommended for expulsion. Two appeals — one to school system administrators and a second to the St. Tammany Parish School Board — were unsuccessful.

But DeCossas, a member of the National Honor Society and the track team, wasn’t done fighting.

His parents have filed a federal civil rights lawsuit in New Orleans, alleging that school officials violated their son’s fundamental rights when they questioned him without informing his mother or letting him know of his Miranda rights to remain silent and to have an attorney present.

The suit, filed by Covingtgon lawyer Fred Salley, also singles out information gleaned from the cellphone, saying it belonged to DeCossas’ father and that administrators had no right to search it in the first place, calling evidence gathered from the text conversation “fruit of the forbidden tree.”

The suit also alleges that Matthew was denied due process, calling the school system’s appeals process a “sham” established to favor school administrators’ point of view and deny students the ability to present evidence or have the assistance of counsel.

A school system spokeswoman refused to comment, citing the pending litigation.

A spokesman for Sheriff Jack Strain, whose office supplied a school resource officer who is named as a defendant, also refused comment.

The school system’s handbook says state law prohibits the use of cellphones on school property and that even possessing one is against the rules. Violation of the rule, according to the handbook, can result in confiscation of the phone, detention or suspension.

The School Board reserves the right to examine the contents of any cellphone found at school, according to the policy.

The handbook also says that school administrators have leeway to punish off-campus behavior that affects the school’s “learning environment,” but it absolves them from responsibility for supervising off-campus behavior.

DeCossas admits to trying to buy Vyvanse from a friend, but he says he did it off-campus. And, he says, what he bought wasn’t Vyvanse but likely just a vitamin supplement — that the seller lied to him.

In a letter recommending that DeCossas be expelled, Assistant Principal Michael Astugue wrote that DeCossas admitted buying Vyvanse from another student off-campus and taking it and then buying it again on Jan. 4 on campus.

DeCossas said he felt pressured by Astugue, Administrative Assistant Leonard Tridico and school resource officer Bryan Gerchow to admit to something he didn’t do after they repeatedly pulled him out of class and pressured him to confess.

The lawsuit says the defendants “called DeCossas back and willfully and in maximum bad faith, conducted another unauthorized, illegal, forced detention and forced interrogations without (his) having been advised about any of his legal rights or provided any opportunity for even a phone call,” the suit says.

DeCossas was never read his Miranda rights, which the suit says was required because of the allegation of drug possession or use.

When DeCossas appealed, he found a process stacked against him, the suit says. The first hearing, before Kevin Darouse, a school system administrator, was a “sham” that “did not even attempt to provide procedural and substantive due process,” the suit alleges.

A Feb. 18 hearing, before the full School Board, was similarly biased, it says. That hearing culminated with School Board member Neal Hennegan telling DeCossas and his parents that the School Board had never lost a court case and that they were getting bad legal advice if they considered filing a suit, according to the federal complaint.

The suit asks the court to order the school system to expunge all disciplinary records from DeCossas’ record and return him to school, as well as monetary damages. It has been assigned to U.S. District Judge Nannette Jolivette Brown.

Follow Faimon A. Roberts III on Twitter @faimon.