[boutad]

Why did BBC put quotes around the word arrested in the title?

[dharmab]

BBC's style guide puts quotes around any part of a headline that is reporting on what others have said.

[testvox]

Generally when newspapers put quotes around a word like that it means they are using a word quoted directly from a source.

[cavanasm]

Probably because there's a dispute over whether anyone was actually arrested, or if they arrested the wrong person, because the journalist who received the video says his source has not been arrested.