Nathan Matthews, the stepbrother of missing 16-year-old Becky Watts, has been charged with her murder, Avon and Somerset Police have said.
His girlfriend, Shauna Hoare, 21, also known as Shauna Phillips, has been charged with attempting to pervert the course of justice reported BBC.
The pair, of Cotton Mill Lane, Bristol, are due before magistrates on Thursday.
Four other men and a woman, all in their 20s, are still being questioned on suspicion of assisting an offender.
Mr Matthews and Ms Hoare are due to appear at Bristol Magistrates Court at 10:00 GMT on Thursday.
Becky, who was described by her family as “wonderful”, was last seen on 19 February and was reported missing the following day.
On Tuesday, body parts were found at a house in Barton Hill, Bristol.
Floral tributes have been left outside Becky’s home and near the house where the body parts were found.
St Ambrose Church, near the family home, is to be opened until 21:00 GMT, and again from 10:30 to 21:00 on Thursday, for people to light candles in the 16-year-old’s memory.
A book of condolence has also been placed there.
The Right Reverend Mike Hill, Bishop of Bristol, paid tribute to Becky’s family and said he had been “deeply” affected by the death.
“I feel sure that people both of faith and of no faith will join with me in wishing to support the friends and family of Becky Watts,” he said.
On Wednesday morning, magistrates granted police a further 24 hours to question the two men aged 29, two aged 23 and a woman aged 23 who had been arrested earlier in the week on suspicion of assisting an offender.