A registered nurse at the Rehabilitation Institute of Chicago has been charged with sexually abusing a soldier with quadriplegia who cannot speak.

Dioscoro Flores, 39, allegedly fondled the man, 24, twice between July 4 and Aug. 6 in the soldier's room at the hospital at 345 E. Superior St., according to Cook County prosecutors.

The soldier, who has been at the institute since June, was able to let his father know what happened by using eye motions and a "spell board," according to a police report. The father went to staff, who told him an internal investigation would be conducted and that Flores would not be working near his son, the report said. The father also contacted police.

Flores was arrested this week and charged with felony aggravated criminal sexual abuse. At a hearing Thursday at the Leighton Criminal Court Building, he was ordered held on $50,000 bail.

The victim's father said his son told him about the abuse a day after the second alleged incident in August.

"It was shock at first and then anger afterward," said the father, who asked to remain anonymous to protect the identity of his son. "You know ... just kind of knowing that something like that could have happened.

"The first initial shock was just, did you just tell me what you told me? Because my communication with him isn't really easy," the father said.

His son raises his eyes for yes and lowers them for no, and he also uses a board to spell out questions.

"I asked him all the questions and basically I stewed on it and I let the (hospital) administration know," the father said.

Then he asked his son what he wanted to do.

"He told me, 'Yes, I want to file charges.'"

"I'm proud of him for saying something,'' his father said.

He believes Chicago police, prosecutors and the institute conducted a thorough investigation.

"The police and the state's attorney's office have been very outgoing with me and keeping me updated with what's going on,'' he said. "I think they've done a good job."

"They are they are the No. 1 rehabilitation place in the country,'' he said of the institute. "They do wonderful things there.''

His son, who remains an active member of the military, was a sharpshooter and did a tour of duty in Afghanistan from June 2011 until August 2012. The father said his son suffered an injury in May that left him a with quadriplegia, but he didn't want to go into detail.

The father said the hospital taught both him and his son how to communicate with one another during his first week there.

"Mentally, he's 100 percent there,'' he said.

The father, who said he does his best to stay upbeat, hopes his son will be able to speak down the road.

"It's life. ... You learn to adapt and move on. You never know one day to the next what's going on. ... With our family, we've learned to adapt," he said. "We're working on getting him back home.''

Tribune reporter Steve Schmadeke contributed.

rsobol@tribune.com