Key events in Joanna Yeates investigation

This is how events have unfolded following the disappearance of 25-year-old landscape architect Joanna Yeates from Bristol:

Friday December 17

6pm: Miss Yeates, 25, leaves the architectural firm where she worked with boyfriend Greg Reardon, 27, and joins colleagues in the Ram pub in Park Street for a drink.

8pm: She leaves the Ram to walk the 20-minute journey home from the city centre to Clifton.

8.10pm: Miss Yeates is caught on CCTV popping into a Waitrose supermarket in the Clifton Triangle.

8.30pm: She uses her mobile phone to ring her best friend Rebecca Scott and arranges to meet on Christmas Eve.

8.40pm: At a Tesco Express on Regent Street in Clifton Village - about a quarter of a mile from her flat - Miss Yeates buys a pizza, which is missing. She then visits a nearby off-licence to pick up some cider.

Police believe she returned home to her flat in Canynge Road, which she shared with Mr Reardon. A receipt from Tesco was found in the flat, along with a cream-coloured coat she had been wearing and her mobile phone and keys.

Sunday December 19

Mr Reardon reports Miss Yeates missing when he returns to Bristol from a weekend away visiting relatives in Sheffield.

Monday December 20

Avon and Somerset Police make their first appeal for information, saying they are concerned for her safety because it is out of character for her to go missing.

Tuesday December 21

Miss Yeates's parents appeal directly to their daughter, saying: "Jo, whatever the reason that you have not been in touch over the last few days, we want you to know that we love you dearly and are desperate to know that you are safe and well."

Wednesday December 22

Mr Reardon makes an appeal, saying: "I desperately want her back - I thought we would be together forever."

Specialist officers search the couple's flat, as well as the snowy Bristol Downs and Avon Gorge.

Thursday December 23

Miss Yeates's parents make a second tearful appeal and reveal fears their daughter has been abducted.

Detectives say that when Miss Yeates was in the Tesco Express she bought a Tesco Finest tomato, mozzarella and basil pesto pizza. There was no trace of the pizza, the wrapping or the box in her flat.

Friday December 24

Police release new CCTV footage showing Miss Yeates buying the pizza.

Christmas Day, Saturday December 25

A couple walking their dogs in the Failand area of North Somerset, three miles from where Miss Yeates went missing, find a body.

Sunday December 26

Police announce they are "satisfied" the body found is that of Miss Yeates.

Monday December 27

The family of Miss Yeates lay flowers at the spot where her body was found.

Tuesday December 28

Police announce that Miss Yeates died as a result of strangulation and officially launch a murder investigation.

Wednesday December 29

It is reported that Miss Yeates's landlord Chris Jefferies saw her leave her flat with two people on the night she disappeared. He later denies the sighting, saying it is a "serious distortion" of what he told police.

Police disclose new CCTV footage of Miss Yeates buying cider at an off-licence on the night she goes missing.

Thursday December 30

Police arrest Mr Jefferies on suspicion of murdering Joanna Yeates.

Friday December 31

Police reveal they have been granted more time to question Mr Jefferies.

New Year's Day, Saturday January 1

Miss Yeates's family issue a statement expressing their grief that their daughter has been "stolen" from them but say they are confident her killer will be caught.

Mr Jefferies is released on police bail pending further inquiries.

Sunday January 2

Police warn women not to walk home alone after dark as Miss Yeates's killer remains at large.

Monday January 3

Police say they have found no evidence Miss Yeates was sexually assaulted, suggest more than one person may have been involved in the murder, appeal for help in tracing a 4x4 vehicle seen near to where her body was discovered and reveal they still do not know when and where she died.

Tuesday January 4

Detectives launch a national campaign on Facebook to appeal for witnesses.

Wednesday January 5

Police reveal they are investigating whether Miss Yeates could have been strangled with her own ski sock - which her killer might then have kept as a trophy.

Friday January 7

Officers talk to more than 200 people as they retrace Miss Yeates's last steps three weeks after her disappearance.

Saturday January 8

Her parents say their daughter's killer has robbed her of a future as a wife and mother. Her brother, Chris Yeates, says he has been left in a "surreal hole of despair".

Wednesday January 12

Miss Yeates best friend Rebecca Scott, the last person to speak to her, says she is "desperate to see justice done".

Monday January 17

Land Registry documents show the killer could have entered and left Miss Yeates's flat without being seen by any of her neighbours.

Tuesday January 18

Mr and Mrs Yeates say their daughter probably knew her killer and urge anybody who knows somebody who has reacted strangely to the murder to come forward.

A reconstruction of the final steps of Miss Yeates was created for BBC's Crimewatch programme.

Meanwhile, detectives said that tests revealed she did not eat the Tesco Finest pizza she was seen buying on her way home just before she went missing.

Wednesday January 19

Police said that more than 300 people made calls to the Operation Braid incident room since filming started on a reconstruction of the 25-year-old's final movements.

Thursday January 20

A 32-year-old man was arrested on suspicion of the murder of Miss Yeates.