Police have appealed directly to two people wanted in connection with a fatal shooting to give themselves up.
Donna Broadway, 26, and her brother-in-law John Broadway, 37, are being sought by police following a double shooting on Thursday night at the Chubbards Cross caravan park, near Ilton, north of Ilminster, Somerset that left Wilfred Isaacs, 50, dead and another man in his 20s injured.
Detectives immediately launched a hunt for Donna Broadway's husband, Charlie, 23, and he handed himself into police on Friday afternoon and has been arrested on suspicion of murder and attempted murder.
Officers have now released a photograph of Donna Broadway and re-released a photograph of John Broadway.
Detective Superintendent Andy Bevan, who is leading the investigation, said: "This is still a major rapidly evolving investigation involving a large team of detectives, our neighbourhood policing teams and armed officers, who are supporting our comprehensive searches for Donna and John.
"Our inquiries are not confined to the Avon and Somerset force area and we're following up all possible leads as they materialise.
"We're grateful for the continuing support we're receiving from all our partner agencies and fully recognise the impact this inquiry will be having on the local community.
"I want to reassure the public that we'll leave no stone unturned in our quest to establish the full circumstances behind this tragic event.
"A vast amount of work is 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.
"In addition to the search for Donna and John, we're 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.
"We're continuing to support the victim's family and I'm grateful for the support they've shown our investigation team. Our thoughts are with them at this devastating time," Mr Bevan said.
"I would urge the public to report any sightings of Donna or John Broadway to us immediately via 999 quoting 1051 of May 5.
"I would also like to directly appeal to Donna and John to hand themselves in as our investigation is uncovering new intelligence all the time, so it's only a matter of time before they are found."
Three people - two men and a woman - remain in custody for questioning in connection with the incident.