On the Supreme Court, John G. Roberts would be called on to deal with some of the loftiest issues of U.S. jurisprudence. During his career in the District, he ruled on a case that hinged on one of the simplest of human actions: the eating of a single french fry.

Last October, Judge Roberts spoke for the U.S. Court of Appeals for the D.C. Circuit in the case of the girl who was arrested at the age of 12 after she was seen popping a french fry into her mouth in a Metro station.

Roberts, writing for himself and for two other judges, upheld the constitutionality of the Oct. 23, 2000, arrest of Ansche Hedgepeth. Her encounter with the Metro Transit Police drew national attention and was frequently condemned as an example of law enforcement excess. The policy that led to her being handcuffed was later changed.

While upholding the legality of the Metro police action, Roberts -- who was nominated yesterday to fill the high court vacancy created by the retirement of Justice Sandra Day O'Connor -- showed that he did not necessarily give it his personal stamp of approval.

"No one is very happy about the events that led to this litigation," Roberts wrote in his opinion.

"A 12-year-old girl was arrested, searched and handcuffed," he wrote. "Her shoelaces were removed and she was transported in the windowless rear compartment of a police vehicle to a juvenile processing center, where she was booked, fingerprinted and detained until released to the custody of her mother, some three hours later -- all for eating a single french fry in a Metrorail station."

The judge wrote that Ansche was "frightened, embarrassed and crying."

However, Roberts wrote, the question before him and his two fellow judges was not whether Metro's policies on enforcing a rule against eating in the transit system were appropriate.

What came before him on an appeal from a District Court ruling was simply whether Metro's policies violated Ansche's constitutional rights under the Fourth and Fifth amendments. The Court of Appeals, he wrote, concluded that they did not.

Ansche's mother, Tracey Hedgepeth, said last night that she had not heard of the nomination and did not wish to comment, adding that she and her daughter have "put that incident past us."

In the 2000 incident, Metro Transit Police officers were posted at the Tenleytown-AU Station on the Red Line as part of a week-long operation to catch students snacking and breaking other Metro rules.

The station, near Deal Junior High School, which Ansche attended, was the source of transit riders' complaints about teenage rowdiness. Ansche was headed home from school when she was arrested.

Police said at the time that D.C. law required that minors caught eating on Metro or in stations be taken into custody.

Metro has modified its policy to permit written warnings and a warning to the juvenile's parents.

Ansche Hedgepeth, with mother Tracey Hedgepeth, was 12 when she was arrested.