A man and a woman arrested over a double murder inquiry in which a father and son were shot dead at home have been released with no further charge, say police.
The two men - Gary Dunmore, 57, and his son Josh Dunmore, 32 - were killed in separate shootings in Cambridgeshire on Wednesday night.
Within four hours police had arrested three people on suspicion of conspiracy to murder.
On Friday, police said a 27-year-old man and a 33-year-old woman had been released from custody and would face no further charge.
A 66-year-old man of no fixed address, who was arrested in Worcester, remains in custody.
Police were first alerted at about 9pm on Wednesday to reports of gunshots in Meridian Close in Bluntisham, and arrived to find a 32-year-old man dead with gunshot wounds.
Less than 40 minutes later, they were called to The Row in Sutton, about six miles away, where they found a 57-year-old dead with gunshot wounds.
They were later named locally as builder Gary Dunmore and his son Josh, who also works in the trades.
Tributes have been left to the pair outside their homes, with flowers and cards building up.
Cambridgeshire Police said post-mortem tests on the dead, who have not been formally identified, will take place at Peterborough City Hospital on Monday.
Det Ch Supt Jon Hutchinson said on Thursday the “primary line of investigation” related to a “familial issue”.
“It’s been widely reported in the media that this may relate to a custody battle,” he said. “I can confirm that is an active line of inquiry for us.”
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