A huge detention center capable of housing 3,000 people - those awaiting trial and others serving lesser sentences - is under construction in Tokyo.
The $400 million facility is in a residential neighborhood in Tokyo and will house prisoners charged with minor crimes as well as those charged with more serious crimes.
Questions included whether the glass sheathing, if broken, could be used for weapons or for suicide.
Mark Hill, a representative of Guardian Industries, the company that makes the glass, told the group the lamination process keeps the glass stuck to the polycarbonate interior, even if broken.
RCI Warden Joseph Sacchet said there has been no history of the glass breaking and even if it did, there is wire mesh inside.
RCI Chief of Security Rod Sowers said that since 1983 when the prison opened there have been three unsuccessful attempts to get out through the glass.
"Housing Unit 4 at RCI is a model in this state," Sowers said.
The glass is being considered for use in other prison areas such as recreation halls, Sacchet said.
"We wanted to visit your facility because we want to use this enhanced glass ... it's a human rights issue," prison technician Yukitoshi Yoshikawa said through an interpreter.
Both the Maryland and Japanese prison officials agreed that glass instead of bars improves the atmosphere for the inmates.
"Your inmates look happy here," Takahashi said through the interpreter. "I think that's because of the way they are treated."
The problems involved in building and running prisons were similar for officials of the two countries.
Both are worried about things like aging prison populations, increased health care needs, wider doorways to accommodate wheelchairs. And both are wrestling with limited resources to meet those needs.