A Hyde Park man will spend more than a decade behind bars after a Suffolk Superior Court jury convicted him of raping a young girl multiple times between 1998 and 2001, District Attorney Daniel F. Conley said.

FRITZ OLMANDE (D.O.B. 8/13/60) was convicted yesterday of four counts of rape of a child and one count of indecent assault and battery on a child. The convictions followed a three-day trial and about a day of deliberations.

“Cases of delayed disclosure are some of the most challenging we face as prosecutors and some of the most wrenching for the victims,” Conley said. “The offenders use shame and fear to escape accountability, and those feelings still linger for victims years or decades after the fact.”

Suffolk Superior Court Judge Frank Gaziano sentenced Olmande to 10 to 12 years in state prison followed by 10 years of probation upon his release. Olmande must also register as a sex offender and provide a sample to the state’s DNA database.

Assistant District Attorney Laura Montgomery of Conley’s Child Protection Unit showed that Olmande was romantically involved with one of the victim’s family members when the victim was between the ages of 5 and 7 years old. During that time, he would frequently spend the night at the family member’s Jamaica Plain home.

Montgomery proved that Olmande exploited his relationship with the girl’s family to sexually abuse her when she was left in his care. Olmande told the girl not to tell anyone about the abuse, which would be “their secret.”

“That instruction is practically an abuser’s trademark,” Conley said. “Children need to know that some secrets weren’t meant to be kept, and that their parents will love them no matter what.”

Olmande’s relationship with the family member ended in 2003, the evidence showed, and so did the abuse. The victim kept the secret until she was in the sixth grade and told a friend from school. About two years later, in 2008, she saw the defendant around town and told her mother about the abuse. Her mother then notified Boston Police. The victim is now 18.

The case went for further investigation before the Suffolk County Grand Jury, which returned indictments in late 2009.

Eliany Colon-Vargas and Kate Lagana were the DA’s assigned victim-witness advocates. Olmande was represented by attorney Earl Howard.