David O'Donnell is a City of London bounty: a church vandal who, with his brother Matthew, has been stripping organ pipes from every church in the district. Kidnap him and bring him to Abberline alive.
O'Donnell's parents abandoned him on a church's steps when he was a child, and he has hated churches since. He and Matthew now steal organ metal, partly out of spite for the music Matthew cannot stand.
He claims they only took a bit of metal and that Charles Babbage would approve, since nobody likes organ music anyway. If he gets free he shouts for his brother. Once recaptured he tries to pin everything on Matthew.
You find David talking with his brother Matthew about one last night of stealing, mocking the old men whose organ music they hate. Matthew's line about holding a candle to the Devil hints that he knows how far David has gone. Only David is on Abberline's list, so leave the brother be and focus on getting David to the carriage.
Bloody Nora oversees the City's Blighters. O'Donnell is one of three bounties here with Harvey Hughes and Maude Foster; the Templar hunts are Thomas Blackroot, Eveline Dipper and the Slaughterhouse Siblings, and the strongholds are Field Lane, Black Swan Yard and Rosemary Lane.
The only optional objective is bringing him back breathing. His escape plan is to call for Matthew, so get some distance between the two brothers before he has a chance to wriggle loose. A dead O'Donnell still counts for the bounty but costs you full sync.
Harvey Hughes
Harvey Hughes is a City of London bounty: a loan shark with a Blighter escort who lends at ruinous interest and sends defaulters to the poorhouse. Kidnap him and hand him to Abberline alive.
Maude Foster
Maude Foster is a City of London bounty hunt for the fastest pickpocket in the city. Police are already combing the street for her when you arrive; kidnap her before she bolts and get her to Abberline alive.
Albie Vassell
Albie Vassell is a Southwark bounty for a street racer who has killed rivals to win. Kidnap him mid-argument with a reluctant sponsor and deliver him to Abberline alive.
Anna Abramson
Anna Abramson is a Southwark bounty hunt for the ringleader of a gang of child pickpockets. Kidnap her and take her to Abberline alive.