FBI Agent Rigby
Rigby is a veteran FBI agent with many years on the force. He always follows the rules, sticks to the facts and questions anyone who stands between him and the truth. He hasn't moved as high up in the agency as he'd like because of a mistake still haunting him -- the kidnapping of a 17-year-old girl in West Virginia. He took responsibility for the botched case but is still paying the price for his mistake by failing to get a higher agency position. Though he would prefer non-law enforcement agents (i.e. private investigators) to leave the case-solving to the FBI, Rigby begrudgingly recognizes that people like Michelle Maxwell and Sean King may have unique skills to catch criminals. Rigby's partner is Agent Carter, so far the longest partnership Rigby has sustained with another FBI colleague. Though the two men see very differently when it comes to investigation and seeking outside help, they do work together quite well.
Sean King and Michelle Maxwell helped Rigby and his partner Agent Carter solve the murder of Ted Bergen and helped uncover illegal dealings within government and corporate agencies -- a huge coup for his crime-fighting reputation.
Rigby pulled Michelle Maxwell in for questioning (who brought along her partner and lawyer, Sean King) after a European politician, Nikoloz Arziani, was shot at. Maxwell has a history with Arziani, and he and Agent Carter found evidence connecting the P.I. to the case. Maxwell was later cleared of any charges and Rigby and Carter joined forces with her and King to discover the truth behind Arziani's murder attempt.
Rigby worked with King & Maxwell in order to solve the mystery behind his partner's arrest and suspension. Though the P.I.s took a few shortcuts, Rigby followed all the proper legal channels to gather enough evidence to put the congressman and his lackey, FBI agent Steve Gibson, behind bars, and get Carter back to work.
Rigby asked for King & Maxwell's help on a kidnapping case, especially since he's had bad luck successfully solving these types of cases (see Rigby's bio above). He also had to work with kidnapping expert Joan Dillinger (Sean's ex-flame and ex-partner), in order to make the victim's family happy. Luckily, this case ended better than the one he failed to solve years earlier, by thinking outside of the box with Sean and Michelle's help.
He may not have wanted their help, but Rigby sure got it when people connected to Sean's old Secret Service unit were coming up dead. Rigby may have resisted at first, but King & Maxwell's out-of-the-box thinking, plus Sean's connection to the case, helped the FBI arrest the murderer (the father of a deceased Secret Service agent).
After a D.C. tabloid blogger is murdered, Sean contacts his FBI sources, Rigby and Carter for backup. Rigby continues the investigation of the murder, even bringing in a suspect connected to Congressman Bradley Ritter. Sean decides to wear his lawyer hat and represent the suspect while in Rigby's care in order to get inside information about everyone involved with Ritter's campaign.
Rigby may not enjoy the company of King & Maxwell, but the FBI agent loves talking with Michelle's older brother, J.T. The P.I.s work to solve the mysterious case of Tommy Smith and his place in the Witness Protection Plan and visit Rigby to get some answers. Though he cannot confirm nor deny Tommy's spot in the program with King & Maxwell, he doesn't mind sharing what he does know with J.T., and J.T. only.
Rigby gets involved in Michelle and Sean's missing cellphone case, but the government agent gets put in his place after the client, head of the country's intelligence agencies, orders Rigby to stay out of Sean's way. Though the move was a slight blow to the ego, Rigby is nothing but professional and steps in to make the arrest when the time comes.
As Sean so eloquently put it, when it comes to Rigby's boss, Wallace, "He's like the Rigby to your Rigby." When a witness is murdered inside the FBI compound, Wallace is ready to put all the blame on Agent Rigby. He relies on Sean and Michelle's quick thinking and nontraditional resources to help find the killer and a new witness. He even gets shot in the chest (protected by a bulletproof vest) during his pursuit of the truth. Though the agent never gets too emotional, Rigby was definitely appreciative for the help from his P.I. pals.
Looks like Rigby has a heart after all. The hard-shelled FBI agent seems to have a soft inside as it turns out he is the one who sent the Ritter evidence to Sean anonymously. He knows how the assassination has tormented Sean for years, and he took a risk sending official FBI evidence to the P.I.