Andrew Boutros simply wanted to give back to his country.

After five years as a lawyer in private practice, the first-generation American decided he could best give back as a federal prosecutor. He sought jobs where he would face “tough, sophisticated cases.” He vowed to take the first offer. And it came from Chicago.

“That first call came from (former U.S. Attorney) Patrick Fitzgerald,” Boutros said.

Boutros arrived here Jan. 1, 2008. And since then, he has faced some of the toughest, most sophisticated cases at the Dirksen Federal Courthouse — helping send former Edgewater Hospital owner Peter Rogan to prison for 21 months and online Silk Road drug dealer Cornelis Jan “SuperTrips” Slomp to prison for 10 years.

But earlier this month, Boutros ended nearly eight years of service at the U.S. Attorney’s Office to become a litigation partner and co-chair of a white-collar, internal investigations and false claims team at Seyfarth Shaw LLP. The new job means Boutros will also spend time in Washington, D.C., but he calls Chicago home.

“I’ve fallen in love with the city,” Boutros said.

The former federal prosecutor said he has been hired to “build out” a practice at Seyfarth Shaw, along with partner Karen Y. Bitar, to handle “all varieties of enforcement actions,” conduct internal investigations, help clients develop best practices and ultimately “stay out of trouble.”

“An ounce of prevention is worth a pound of cure,” Boutros said. “I think that’s going to be very important.”

T. Markus Funk, a former federal prosecutor, recalled in an email last week that Boutros’ work at the U.S. Attorney’s office got off to an auspicious start when he found himself questioning an “old-time, battled-tested” street gang leader who had been cooperating with the feds. That gang leader fainted under the intensity of Boutros’ interrogation.

The 7th U.S. Circuit Court of Appeals later documented the incident in a written opinion.

“I recall thinking that, if Andrew managed to dissect such a hardened criminal, what could he do in the courtroom?” Funk said. “As it turned out, Andrew did not disappoint.”

Fitzgerald, who served as Chicago’s U.S. Attorney between 2001 and 2012, called Boutros “very smart” and “very, very committed.”

“I think when he gets into a case, he really sort of sinks his teeth into it,” Fitzgerald said.

U.S. District Court Judge Virginia Kendall also praised Boutros: “Having worked with Andrew on numerous bar association programs, I can say that his keen legal mind is second only to his passion for developing the area of law pertaining to corporate social responsibility. He approaches the law everyday as a vocation, not an occupation.”

Boutros’ work included the prosecution of Slomp, the online drug dealer who admitted he sold more illegal drugs than anyone else on the underground website “Silk Road.” Boutros told a judge in May that Slomp wound up cooperating and allowed the feds to assume his online “SuperTrips” identity.

Boutros also called this month’s sentencing of Rogan, the former hospital executive who hid in Canada for seven years, “a nice bookend” to his career as a prosecutor. Boutros had been on the job for only a few months when he had Rogan’s arrest warrant issued on Memorial Day weekend of 2008.

Rogan’s sentencing hearing became Boutros’ last public act as a federal prosecutor.

Before joining the U.S. Attorney’s Office, Boutros helped launch a Foreign Corrupt Practices Act section at an international law firm in Washington, D.C. He also teaches at the University of Chicago Law School.