A 15-year-old accused of fatally shooting her classmate was upset because the two had recently stopped talking and told police she brought a gun to school because she "wanted her to feel pain like me," according to an affidavit.

Teah Wimberly, a 15-year-old sophomore at Fort Lauderdale's Dillard High School, was ordered held in jail for 21 days Thursday, and will likely undergo a psychological examination before her next court date.

"She's a very troubled young girl and we asked the judge to order a confidential psychological evaluation," said her attorney, Gary Kollin. Wimberly's family was "distraught about the fact that a child has died" and "saddened by the fact that Teah is in custody."

Wimberly is charged with first-degree murder and discharging a weapon on school property in the killing of Amanda Collette, also 15. Officer Mark A. Shotwell, who interviewed Wimberly, wrote in the affidavit that she said the two had been friends, but recently stopped speaking. Investigators said Wimberly shot Collette, then walked to a seafood restaurant to call authorities and turn herself in. Prosecutors are considering charging her as an adult.

Dozens of high school students gathered before classes Thursday for a brief memorial service in Collette's honor. Some students wore black, while others brought flowers and teddy bears. A few said prayers.

The shooting around 11 a.m. Wednesday set off a confused chain of events at the school: Students screamed and ran when the victim fell to the floor, but authorities couldn't immediately confirm a shot had been fired.

Stephan Willis, a sophomore, said the girls were arguing in an outside corridor when Wimberly suddenly pulled out a gun and shot Collette.

"She's a nice girl. She's quiet. She just keeps to herself," Willis said of the victim, whom he said he'd known since elementary school.

Authorities later confirmed the shooting. It was possible a smaller-caliber gun was used and the wound closed around the bullet, said Sgt. Frank Sousa, a spokesman for Fort Lauderdale Police. The school was locked down for a short time, but classes soon resumed.

Wimberly left campus and walked across the street to Captain Crab's Take-Away restaurant where she called authorities and told them "she had shot her friend," Sousa said. Authorities took her into custody at the restaurant and recovered a gun.