School Drug Task Force agents arrested three Tara High School students Thursday in the investigation into an unloaded handgun taken to the school Wednesday, authorities said.

The arrests bring the total number of people booked in the investigation to four, including a 20-year-old man who tried to run over a task force agent near a South Harrell’s Ferry Road apartment complex Wednesday afternoon, said Casey Rayborn Hicks, a Sheriff’s Office spokeswoman.

The 16-year-old girl who allegedly took the unloaded 9 mm handgun to school Wednesday morning with the intention of selling it has not been arrested. Task force agents plan to issue a warrant for her arrest soon, Hicks said.

Investigators say the girl took the gun to school and traded it for a cell phone to Cody East, 18, whose older half brother, Compton East, 20, was arrested Wednesday after he tossed a backpack holding the gun over a fence during a confrontation with task force agents near the St. Jean Apartments off South Harrell’s Ferry Road, an affidavit says.

On Thursday, investigators arrested the three additional teens — Cody East; Caylen Billingsley, 17; and a 16-year-old boy — after learning that all three handled the gun on campus Wednesday before Cody East left campus in possession of the gun, according to Hicks and Parish Prison records.

Cody East, 3233 O’Neal Lane, and Billingsley, 3223 King Bradford Drive, both of Baton Rouge, were booked into East Baton Rouge Parish Prison on a count each of possessing a firearm on a school campus, according to booking records.

The 16-year-old boy’s name was not released. He was booked into the East Baton Rouge Parish Juvenile Detention Center on the same count, Hicks said.

Tips led authorities to the St. Jean Apartments on Wednesday afternoon in search of Cody East. Instead, they found Compton East, Cody’s older half brother, who’s accused of trying to run over a task force agent and crashing into a patrol unit before exiting the vehicle, tossing the backpack and attempting to flee before being caught, an affidavit says.

The four teenagers involved, including the girl, were students at Tara High School, Hicks said.

School officials will dole out disciplinary actions once the Sheriff’s Office completes its investigation, said Keith Bromery, an East Baton Rouge Parish school system spokesman.

There’s “zero tolerance when it comes to weapons in the school because they threaten everybody in the school,” Bromery said.