A man has been charged with the murder of Jayden Parkinson after the 17-year-old girl disappeared almost two weeks ago, police have said.
Ben Blakeley, 22, from Reading, who is said to be Jayden's boyfriend, has also been charged with perverting the course of justice.
He has been remanded in custody after appearing at Oxford Magistrates' Court on Monday.
A 17-year-old male, who cannot be named for legal reasons, has been charged with one count of assisting an offender between 3 December and 10 December.
Specialist search teams backed by helicopters and police dogs have continued to search for Jayden, who has not been seen since she was spotted leaving Didcot train station, in Oxfordshire, on 3 December.
Throughout the weekend, officers have focused their search of an area of farmland just outside the village of Upton, near Didcot, and appear to be particularly interested in a small patch of woodland near the church.
The police's team now consists of 100 officers. Superintendent Christian Bunt said the existing searches could continue for “days” as police strive to discover what has happened to the teenager.
Mr Bunt said the complete lack of any contact or activity from Jayden - she has not used her mobile phone or bank account since going missing - led detectives to believe she may have been killed.
Detective Chief Superintendent Andy Murray said police were focused on tracing a man seen with a large suitcase in a field near Upton in the early hours of 9 December.
Mr Murray said the same man with the suitcase was seen in Didcot about half an hour later.
He is described as about 20, white, about 5ft 6in, of medium to slim build, with short dark hair. The suitcase was about 3ft by 2ft, about 15in deep and light coloured, probably made of canvas material.
Mr Bunt, Oxfordshire police commander, added that officers were also continuing to sift a grassy area of wasteland in the Lydalls Road area of Didcot.
Residential addresses have also been searched and a recycling bin was earlier removed for further examination.
Jayden’s mother Samantha Shrewsbury recently posted a message on Facebook saying: “My baby, my princess, my heart is so heavy, baby girl.
“I just want to see you walk through my door with a 'ta-dar'. I need you little lady, my heart feels so empty without you.”
Mr Bunt thanked the public for their help with the inquiry so far, but urged people not to carry out their own searches as these could prove a risk to the ongoing police investigation.
The teenager, who had recently left home in Didcot to live in Oxford, failed to return to the city on the evening of 3 December, as planned after visiting the town.
Police have pieced together her movements in the run-up to her disappearance, and believe she walked up Oxford's High Street through the town centre, arriving at the train station at 4.07pm, where she then boarded a train to Didcot.
The very last sighting of her is when she left Didcot train station at about 4.27pm.
Jayden is white, of slim build, with shoulder-length dark brown hair and brown eyes. When last seen, she was wearing light-blue faded jeans, a brown hooded top with red lettering on it, a black waist-length jacket, and dark trainers.