Passers-by also joined the chase before cops nabbed the thief.
The Sun
No one else joined the chase.
Globe and Mail
The two people who have been arrested are said to have joined the chase in the street.
Times, Sunday Times
As well as that thread, there's a barely explained government agency joining the chase.
The Sun
Soon more cop cars joined the chase, and eventually forced him off the road.
Times, Sunday Times