Definition: In this task, you will be presented with a passage and have to answer a question based on your understanding of the events inferred from the passage. Try to find the best answer that is most likely to fill in "_". Note that the URLs in the text have been replaced with [Link].
Input: A 78-year-old Connecticut man with a long criminal history was arrested on Friday, but the man's lawyer claimed the arrest was a ruse intended to pressure him to talk about the biggest art heist in U.S. history. Robert Gentile appeared in federal court in Hartford, Connecticut, on Friday and was charged with selling a firearm to an undercover agent. His attorney, Ryan McGuigan, contended Federal Bureau of Investigation agents really want to see what Gentile knows about the theft of $500million in artwork from Boston's Isabel Stewart Gardner Museum 25 years ago. Scroll down for video Robert Gentile's attorney Ryan McGuigan (pictured), said that though his client was arrested on a gun charge, he believes the arrest was a ruse to pressure Gentile to speak about the $500million art heist from 1990Robert Gentile was charged with selling a firearm to an undercover agentBut his attorney claims the arrest was a ruse to get Gentile to talk about the 1990 Boston art heist at the Isabel Stewart Gardner MuseumGentile's house was searched in 2012 and police found a list of the stolen art pieces and their estimated value, as well as police uniformsThe half-a-billion heist remains unsolved and FBI has never come close to finding thievesGardner museum continues to display empty frames, and is offering $5million reward for the return of the works 
 Question:'The _ has been questioning him for years because they.

FBI