Police investigating the fatal shooting of a man at a caravan park have arrested seven people.
John Broadway was arrested on Saturday on suspicion of murder, attempted murder and firearms offences, Avon and Somerset Police said.
Broadway was arrested in Lichfield, Staffordshire, in connection with the inquiry into the murder of Wilfred Isaacs, 50. Two women who were at the same location have been held on suspicion of assisting an offender.
Mr Isaacs was shot dead at Chubbards Cross caravan park, near Ilton in Ilminster, Somerset, on Thursday night in an incident that left another man in his 20s injured.
Broadway's younger brother Charlie, 23, is already in police custody having been arrested on suspicion of murder and attempted murder, having handed himself in to police on Friday afternoon.
A total of seven people are now in custody in connection with the double shooting.
Charlie Broadway's wife Donna, 26, was arrested on Saturday evening on suspicion of assisting an offender, having handed herself in to police.
Detective Superintendent Andy Bevan, who is leading the investigation, said: "We're working round-the-clock to ensure we carry out a thorough and professional investigation into this horrific crime.
"We'll continue to leave no stone unturned in our quest to establish the full circumstances.
"A vast amount of work is still taking place at the scene of the shooting as we're carrying out a large-scale forensic examination in conjunction with ballistic experts, as well as other searches.
"The site remains closed off and these significant inquiries are likely to last several days.
"We're also continuing to look for the weapon used in this crime, which we believe to be a shotgun. If anyone knows where this weapon is they should call us immediately."
A post-mortem examination found that Mr Isaacs died of a gunshot wound to the body.