That girl later told police that during the "exercises," Fomin would instruct her to lie on her back and lift her legs off the floor 10 times before he would reach under her clothing and fondle her, the complaint says. The victim told police that Fomin touched her on more than one occasion.
Detectives also determined that the daughter of the man who made the initial report had been abused. That child, the complaint says, said that during lessons, Fomin would have her lie facedown on his lap and pull her pants down, and that he had exposed himself to her.
A third victim, a boy, told police that Fomin would touch his genitals and sometimes take him to the bathroom, where he would expose himself to the child, the complaint says.
Investigators said they believe Fomin also showed his victims nude photos of children, himself, and his wife, Tatiana Abramova, who also taught piano at the Malvern music school. Detectives said they found the photos described by victims on Fomin's computer.
Fomin is charged with attempted aggravated indecent assault, indecent assault, corruption of minors, child endangerment and related offenses.
In the same 2008 Inquirer story in which Fomin described teaching, a reporter wrote that he gave one of his pupils "a vigorous bear hug and kissed him on the top of his head" after a performance.
Hogan said there could be more victims and encouraged parents of students who may have had contact with Fomin - who police said also gave private lessons at his home on Kimberton Road near Hares Hill in Phoenixville - to talk with their children.
Hogan called Fomin's conduct "classic grooming behavior by a predator, trying to acclimate children to sexual abuse."
Tipsters should contact Chester County Detective James Ciliberto at 610-344-6866.
On Twitter: @morganzalot