By Andrew Kramer

PHILADELPHIA (CBS) — What to expect next in the Russia investigation? A retired Philadelphia FBI agent gave his take.

It’s not unusual to see federal grand juries brought into investigations of this magnitude, says former special agent J.J. Klaver.

“Even in much simpler investigations, grand juries are used to indict individuals,” he said.

But well before indictments are issued, the grand jury has another responsibility.

“It can issue subpoenas that compels people to present records and documents and, in some cases, to appear to answer questions,” Klaver said.

He says no one can refuse to appear before a grand jury if they’re subpoenaed, and if you hoped this investigation would wrap up quickly…

“The fact that the grand jury is involved says that this investigation is not ending anytime soon,” said Klaver.