Investigators say the students sold drugs to that undercover officer -- prescription drugs like Oxycodone, Ritalin, Hydrocodone, as well as marijuana. Among those arrested are Dylan Paul Smilie, Jessica Lee Poteet, Lauren Chelsea Gore, Jose Dorbecker Jr., Jordan Ray Williams, Phillip Jones and Matthew Ryan Hubenak.
Four of the 12 suspects were still in jail Wednesday night.
"So do you have a prescription for Adderall?" we asked 17-year-old Dorbecker Jr. as he was leaving the Brazoria County Jail.
Dorbecker Jr. covered his head and didn't answer questions after his parents bonded him out of jail Wednesday night. Earlier, his mother told us he had a prescription for the amphetamine.
On Wednesday morning, he was arrested and charged with selling almost 5 grams of the stuff to an undercover officer.
"I was shocked because I usually don't see any drugs here," student Ryan Reyes said.
A total of 10 students were arrested at Angleton High School. Brazoria County Sheriff's Office deputies arrested two former students at their homes. Seven out of the 12 are adults, and they include star football player Phillip Jones.
"Phillip got pulled out of my class," student Brendan Starr told us.
It was second period when authorities served the arrest warrants. Starr has known Jones since Little League.
"They're like, 'Sir you're under arrest for selling marijuana to our undercover officer,' which blew my mind," Starr said.
According to school officials, a recent student survey about alcohol and drugs, as well as their known prevalence, compelled them to seek help.
"Nothing we've done has made a significant difference and if you keep doing the same thing and nothing changes, there is something wrong with you," Angleton ISD Superintendent Patricia Montgomery said.
So they instituted mandatory drug testing for some students and placed an undercover officer in the school for four months.
"Had to do everything a student does, from homework to everything else," Angleton ISD Police Department Chief James "Chip" Gayle said.
He was also able to buy marijuana, officials say, as well as prescription painkillers and antidepressants. The students now facing charges are accused of selling and will likely be expelled.
"Go school board, go Angleton, it's been needing to come for a long time," parent Dean Lucas said.
"They could honesty get more people if they wanted to," Starr said.
A total of 28 charges were filed, ranging from delivery of a controlled substance to delivery of marijuana. In addition to the criminal charges, the students will face expulsion.
Out of the 100 random drug tests administered since October, five students have failed. The school district says it will continue to administer random drug testings and other methods to keep students on their toes.
Parents were sent a letter explaining what happened Wednesday.