Superintendent Carter

In the novel The A.B.C. Murders, Superintendent Carter is a senior police officer of the Sussex County Police. He attended a meeting at Scotland Yard hosted by Chief Inspector Japp to discuss what steps the Sussex Police could take in view of the warning from the serial killer "A.B.C." that his next victim would be from Bexhill-on-Sea. Together with Carter at the meeting was his subordinate Inspector Kelsey.

During the meeting, the Chief Constable of Sussex asks Carter what precautions might be taken, and Carter says that it is difficult as they have not the least clue of who the victim might be. Poirot suggests that the victim's name might begin with the letter B.

The Chief Constable tells Carter take note of people whose names begin with B, especially small shopkeepers, keep a watch on all small tobacconists and newsagents run by a single person, and keep tabs on all strangers as far as possible. Carter points out the difficulty of this, as the school holidays were beginning, and many people were coming to Bexhill. However, the Chief Constable says that they must do what they can.

After the murder of Betty Barnard, Poirot and Hastings travel to Bexhill, and are greeted by Superintendent Carter. He had already broken the news to Mr Barnard and Mrs Barnard, and had left them to get over the first shock before being interviewed by Inspector Crome. He also gives Inspector Crome the main details about the case, so that he can begin making his own inquiries.

Portrayals
In the film adaptation of The A.B.C. Murders in Series 2 of ITV's Agatha Christie's Poirot, the part of Carter is played by Peter Penry Jones. As Inspector Kelsey is not cast in this adaptation, Carter was also personally present with Japp and Poirot when examining the crime scene at the beach in Bexhill.

In the anime show ABC Murders, NHK's adaptation of The A.B.C. Murders, there were two officers present at the meeting hosted by Sharpe (Japp) who discuss what they could do about the threat to Bexhill. We can assume that the senior is Carter and the subordinate is Kelsey. The characters are not named and as is common in the anime series, the voice actors behind these minor parts are not credited.