Temporary Detective Chief Superintendent Gordon Lang said James Allen was arrested after an off-duty officer spotted him in South Leeds this morning and urged the public to keep sending in information on the case.
Monday April 23: Police find Colin Dunford, who was last seen alive at around 5pm on Sunday, dead with serious head injuries at his terraced house in Middlesbrough.
Wednesday April 25: Julie Davison, who lived alone, is found dead by her sister at her rented flat in Whitby, North Yorkshire.
Thursday April 26: Cleveland and North Yorkshire Police issue a joint appeal to find Allen after officers link the two deaths.
Friday April 27 - Cleveland Police reveal Allen lived next door to Mr Dunford in Leven Street about a year ago.
Saturday April 28: CCTV images of Allen in Scarborough and Leeds are released. Police confirm he stayed in a bed and breakfast, thought to be the Allerton Croft Hotel in Scarborough, on Wednesday night.
Sunday April 29: Allen, 36, is arrested in south Leeds at 7.20am and held on suspicion of murder.