Detective Harris is assigned to guard Walter Dresden from a killer who is targeting an Army war game team, not knowing Dresden is the killer. Dresden knocks Harris out and holds him for ransom. He's portrayed by Robert C. Kirk.
Searching for Duane Proctor, suspected of abducting Irene Adler, Muldoon is told by Gregson to stay with Duane's brother Isaac Proctor. Isaac shoots Muldoon in his bullet-proof vest and escapes. Muldoon suffers six broken ribs and a punctured lung. He's portrayed by Frank Deal.
Basken asks for Watson's help with a string of robberies and makes it clear that he doesn't want Holmes involved due to his rudeness. However, Holmes sees the case file and solves the robberies in a few minutes. He's portrayed by Peter Hermann.
Investigating the murder of Donald Hauser, Holmes leaves a message for reporter Rosalie Nunez. Finding her dead, Luntz calls Holmes and sarcastically asks him to come to Nunez's apartment as he has some "consulting questions" for him. He's portrayed by Robert Creighton.
After Kayden Fuller is kidnapped and her father killed, with police attending, her mother Allison receives a phone call. Detective notes that the caller ID is a question mark. He's portrayed by Jeffrey C. Hawkins.
After Watson and Gay find a very valuable dinosaur fossil that's placed in storage at the 11th precinct, Park tells Gregson that an officer from I.C.E. is looking for the fossil. He's portrayed by Adam McNulty.
From the 5-3 squad, Loughlin meets Bell, Holmes and Watson at a funeral home where Holmes shows her that a mortician was killed accidentally and Holmes finds a jewel thief pretending to be a cadaver. She's portrayed by Sue-Anne Morrow.
After Melanie Vilkas is found dead with the same torture marks as Kitty Winter, Whitaker, from the 8th precinct, is questioned and rebuked for his lack of effort on Vilkas' missing persons case. He's portrayed by Murphy Guyer.
From the 116th precinct, Homicide Detective shows Watson the crime scene in the murder of Dennis Hicks. Watson deduces that thieves who were robbing apartments across from Hicks' saw his murder. He's portrayed by Jack Gwaltney.
A Narcotics detective undercover in the biker gang "Satan's Brood", Dunning and Detective Lisa Hagen hatch a scheme to rob the gang. After the robbery, Hagen kills Dunning. He's portrayed by Mark Menchaca.
Initially denying Holmes access to a crime scene involving the poisoning of a professor and his students with mushrooms, Lydel and his Captain are amazed with Holmes' incredibly quick deductions. He's portrayed by Austin Durant.
A member of the Long Island police, Sybert provides Bell and Watson with the file on the kidnapping of Beth Stone and watches a surveillance video of Beth's abduction with them and Beth's husband, Aaron. He's portrayed by Curtiss Cook.
Brooks shows Captain Gregson and Holmes a video of a man being tortured into admitting he planned to have sex with a minor and indicates the torturer is pretending to be underaged girls on a dating website. He's portrayed by Alfredo Narciso.
Unwilling to accept Holmes' deductions in the murder of a gang member, she tells Holmes and Watson that analysis of prints on a gun will be delayed due to lab renovations. She later uses their offer of help to get the analysis done quicker. She's portrayed by Debi Mazar.
Rockaway Detective leads Gregson, Holmes and Watson to a huge blood stain on a beach. Believing it may belong to one of Ryan Decker's victims, it's later discovered it was Decker's blood, who was killed by his wife, Carrie Traub. She's portrayed by Ruthie Ann Miles.
In order to get Shinwell Johnson promoted in the drug gang SBK, so he can dismantle it, Watson provides Acosta with evidence that an SBK lieutenant, DaMarco Bridger, murdered a woman that Acosta is investigating. He's portrayed by Leroy McClain.
Head of the Property Crimes division and an expert on stolen artifacts, Mason helps Holmes and Watson track the sale of stolen Revolutionary War antiques in exchange for Holmes solving one of his cases, which he does in a few seconds. He's portrayed by James Monroe Iglehart.
After Hannah Gregson's roommate Maddie Williams is murdered by a serial killer, Captain Gregson pulls together a task force of which Older Detective is a member. He's been investigating the killer for three years. He's portrayed by Gilbert Cruz.
With Bell preparing to leave Major Cases for the US Marshals, Holmes and Watson suggest to Gregson that Romero would be a good replacement. However, Gregson disagrees as Romero is too comfortable skirting the law. She's portrayed by Elena Hurst.
After Holmes is seemingly shot by Odin Reichenbach and falls off a bridge into a river, suited detective tells Detective Bell that the police scuba team is slackening the search. He's portrayed by Luis Moreno.