Police have arrested the landlord of Joanna Yeates on suspicion of her murder.
Retired public school teacher Chris Jefferies, 65, was arrested at 7am yesterday at his flat directly above the basement Victorian property he rented to the 25-year-old landscape architect and her boyfriend Greg Reardon, 27.
The arrest came just 24 hours after Mr Jefferies claimed he had watched as three people left Miss Yeates' flat in Canynge Road, in the upmarket area of Clifton, Bristol, on the night she vanished.
Neighbours have described Mr Jefferies, who sports a distinctive mane of straggly white hair, as a "nutty professor-type" who was active in his community, playing a prominent role in his local Neighbourhood Watch group.
He taught English at Clifton College, just yards from his flat, from the early 1970s before taking early retirement in 2001.
Grimsby-born bachelor Mr Jefferies, an enthusiastic activist for the Liberal Democrats in Clifton, is also a member of the Clifton and Hotwells Improvement Society (CHIS), which campaigns to conserve buildings in the area.
Resident Tony Buss, 51, said yesterday: "Today's news is a shock and surprise."
He said the community had been worried about a killer on the loose.
Another neighbour, a 26-year-old man who did not want to be named, said: "It's all been pretty scary, especially for my girlfriend as I'm away most of the week. It's been pretty scary for her to be home alone."
Referring to Mr Jefferies, he said: "We see him all the time on the road. He's a bit of a nutty professor-type by the looks of it."
CHIS secretary Rosemary Musgrave said: "He's certainly an active member and does come to meetings from time to time. He's not a member of the committee, though."
In 2005 Mr Jefferies was at the forefront of efforts to stop building work on fields near his home. He led the Canynge Road Campaign Group to save the fields from development and wrote a series of letters to Bristol City Council outlining the group's opposition to the scheme.
Ray Lowman, who lives in a flat opposite the mansion where Mr Jefferies and Miss Yeates lived, said: "I'm amazed by it really but also find it quite disconcerting. He is basically a pillar of society. One of the well-known familiar locals."
Mr Lowman acknowledged Mr Jefferies' at times unconventional manner of dress.
"It is one of the problems. His appearance is unusual," he said. "I wouldn't say he was weird but unusual and the hair is an affectation. A very intelligent man, very sharp."
Two cars, a silver Chrysler Neon parked on the street and a grey Volvo S40 that was on his drive, have been removed by police for examination.
Miss Yeates was last seen on December 17 and her snow-covered body was found on Christmas morning by a couple walking their dogs in Longwood Lane in Failand, North Somerset. She had been strangled.
Her grieving parents, David Yeates, 63, and his wife Theresa, 58, said in a statement yesterday they were pleased an arrest had been made.
An Avon and Somerset Police spokesman said: "Police attended an address in Canynge Road and arrested a 65-year-old man on suspicion of murder.
"He has been taken into custody at a police station within the Avon and Somerset force area and detained for questioning."
A 10,000 reward has been offered to help police catch her killer and fresh closed circuit TV pictures were released of Miss Yeates buying cider in a branch of Bargain Booze on the night she vanished.
Anyone with information is asked to contact Crimestoppers on 0800 555 111.