A fourth man has appeared in court charged with the murder of Stephen Green and conspiracy to rob.
Shane Liddy, 18, of Brickley Road, Luton, appeared briefly at Luton Magistrates Court on Wednesday.
He spoke only to confirm his name, age and address and no bail application was made.
Mr Liddy was remanded in custody to appear with codefendants at Luton Crown Court on Wednesday.
Richard McNamara, 18, of Butely Road, Luton and two 17- year-olds who can't be named because of their age will also appear then.
A further three people have been arrested on suspicion of perverting the course of justice. They have been bailed and released pending further inquiries.
Mr Green, 55, of Acworth Crescent, Hockwell Ring, died on Monday May 14 in the Luton and Dunstable Hospital after being admitted there on Bank Holiday Saturday.