A 44-year-old man who purportedly worked as a mentor for middle school students was held at the Baltimore City jail without bond Monday on sex offense charges, after a middle school girl told police he groped her.

Charles D. Shelly, of the 3500 block of Cliftmont Ave., is charged with sexual abuse of a minor and related counts.

The investigation began on Dec. 11 when police received a call from the girl's mother who told them her daughter had been groped by Shelly, whom she described as a school mentor, according to a police report.

The daughter attends Northeast Middle School and has known the suspect for at least a year, police said. The woman told police she became concerned about Shelly last year when she found out he was removing her daughter from school for mentoring, but "was assured that the suspect was a good man and had an excellent track record mentoring young girls and gaining their admittance into the elite all girls Western High School," according to the police report.

The woman told police she and her family grew to trust Shelly and invited him to dinners at their home.

On Dec. 7, after school, police said the suspect drove the girl to a store where he purchased baby oil before driving her to a parking lot inside Herring Run Park. The girl said they began watching Christmas movies on an iPad before things got "weird." Police said the suspect began touching the girl's back and breasts and rubbed baby oil on her back. He realized the park was about to close and drove to the parking lot at Lake Clifton High School, according to the police report.

There, he attempted to kiss the girl on the side of her neck, police said, who added that the suspect stopped when the girl said she was uncomfortable and asked to go home. The girl told police this behavior has happened previously, but she did not give details of those incidents.

School police were also notified of the incident. School officials have denied that the suspect had any official role as a mentor at the school.

Luke.Broadwater@baltsun.com

Twitter.com/lukebroadwater