ST. AUGUSTINE, Fla. - A 28-year-old Nease High School teacher who was fired earlier this month was arrested Thursday and charged with two counts of sexual activity with a minor. Dionne Younce, the former physical education teacher, was booked into the St. Johns County jail and ordered held on $200,000 bond. More St Johns County Headlines School board fires Nease teacher under investigation Student says teacher sent nude Snapchat photos Nease High teacher suspended during investigation Bill Lodise, whose son is a sophomore at Nease, was disappointed to learn that the rumors about the school's PE teacher were confirmed by her arrest. "This day in social media, it's kind of easy to do. But still, doing that with students?" Lodise said. "Obviously, it's taking advantage of somebody who's not mature enough to make those decisions; wise decisions." The Sheriff's Office said it began investigating Younce on Jan. 20 after getting getting three or four letters from students that she had an inappropriate relationship with at least one student. Detectives were told by a 17-year-old that he had sex with her twice at her apartment on Ponte Vedra Boulevard. Special Victims' Unit detectives questioned Younce and her apartment was searched on Wednesday. Evidence gathered resulted in an arrest warrant. Neighbors who noticed deputies in the area, but didn't know they were targeting Younce. "There's actually been a lot of cops here this week. Maybe three times this week," Aaron Clegg said. "It's a shame, I guess. You hear about that stuff all the time, but you don't think it was your neighbor." Younce was fired by the St. Johns County School Board earlier this month after three students said Younce messaged them and sent them text messages, beginning last fall. One of the students, whose name was not released, said Younce also Snapchatted with him. He said it was “casual," but then it turned “sexual” after a while. READ: Nease teacher suspension letter "We started sending nude photos to each other, and we did that for a while --- until rumors started to break out," one student wrote. He said that he and Younce “started sending nude photos to each other” until rumors started, and she told him not to talk about it because she didn't want to get caught. He said he thought the situation was over until he received a Snapchat message during a basketball game of a picture of Younce wearing only a bra. He said he realized the same message had been sent to a fellow football player. Another one of the student statements said that Younce called him at night to talk about sports. He said "to be completely honest, (she) used to sometimes be, I think, under the influence (when she called)." A day after the students gave their statements to school officials, Younce was notified by letter that the district had “elected to dismiss (her) from employment.” The School Board finalized that decision without comment as part of the consent agenda at its February meeting. Younce's neighbor was shocked to learn what she is accused of doing. "She's a sweet girl. She goes to work every day," Cregg said. "It's just one of those things that you don't know that someone's doing bad until you hear about it."