A 13-year-old girl reported she sent photos of herself in underwear to a St. Paul classroom assistant, that they had a long hug and that he touched her clothed buttocks, and he once asked to kiss her but she told him no.

Police received a report about the Capitol Hill Magnet School staffer, who was also a coach, in April and the school district put him on leave. At the end of August, the Ramsey County attorney’s office declined to file charges against Jonathan G. Ball, 33, citing insufficient evidence.

An investigator who conferred with prosecutors wrote in a police report that they determined without “further disclosure or evidence, there are no criminal action disclosed, however they are inappropriate for a school employee.” St. Paul police have closed their investigation into Ball.

Ball, who was not arrested, did not give a statement to police, according to the department’s reports. An investigator talked with Ball by phone on May 9 and asked him to come in to speak with him.

“Ball expressed surprise that he had done anything inappropriate and said he would need to think about whether he wanted to talk to me,” the investigator wrote. Ball told the investigator he would call back, but did not.

The investigation began after Capitol Hill Magnet’s principal reported to police on April 26 “an alleged sexual relationship” between a staff member and a seventh-grader, according to a police report. The principal said another student told him the day before that “she believes there was something going on with coach Ball” and a student, the report said.

The student reported seeing “very disturbing pictures and text messages” three weeks ago and said she hadn’t told the principal earlier because “she just figured the whole school knew,” according to the police report.

A school counselor talked to the student who was alleged to have been communicating with Ball, and the girl gave her cellphone to the counselor. The counselor said the girl’s phone contained numerous naked photos of herself, no text messages between her and Ball, and two photos of Ball — in which he was clothed — in the phone’s deleted section.

Police collected the phone and, with permission of the girl’s mother, analyzed it for further evidence, but found nothing relevant.

Another staff member showed police there was school video surveillance of Ball and the girl on April 20. They were walking side by side “with what appears to be … their arms around each other at different times as they walk,” according to a police report. The school reported that Ball should have been in a separate part of the building, assisting a teacher at that time.

The 13-year-old, who told police she had known Ball since November, met with a nurse at Midwest Children’s Resource Center, which specializes in assessing child victims. The teen said Ball began following her and other students on Instagram, and they then began chatting on Snapchat, according to a police report.

“Their chatting was personal in nature and not related to school,” the report continued.

The teen said she sent a photo to Ball and he commented about her buttocks, according to the police report. She said he never sent her any photos and they didn’t meet outside of school, but she would sometimes skip class to meet him in school, the report said.

An investigator spoke with the girl’s mother on April 27 and told her about the status of the investigation. “(S)he agreed that the facts/circumstances were definitely in the ‘grey’ area of the law,” the investigator wrote.

Dennis Gerhardstein, a spokesman for the Ramsey County attorney’s office, said Monday they were unable to bring felony charges in the case “because there was not sufficient admissible evidence that would allow us to prove each element” of a criminal sexual conduct case “beyond a reasonable doubt.”

Ball remains on leave from the school district and is the subject of a complaint that remains under investigation by the district, according to Toya Stewart Downey, school district spokeswoman.

Ball did not return calls from the Pioneer Press seeking comment.