Police made three arrests after two men were shot dead in targeted attacks at separate locations in Cambridgeshire on Wednesday.
The body of a man, 32, was discovered in Bluntisham after reports of gunshots just after 9pm.
The body of a second man, aged 57, was found at 9.37pm in nearby Sutton after police were again alerted to reports of gunshots.
The sites in Bluntisham and Sutton are about 10km apart.
Police said they were not in a position to name either victim because formal identification has not yet been carried out.
Officers later arrested three people on suspicion of conspiracy to murder.
A man, 27, and a woman, 33, were arrested in Cambridge early on Thursday and a man, 66, was detained in the Worcester area.
The homes where the men were shot have been cordoned off and police have stepped up their presence in the area.
Gordon Murray, who lives near two semi-detached houses that have been sealed off by murder detectives in Sutton, said he saw police cars "racing down" the road and armed police shouting on Wednesday evening.
The 62-year-old support engineer said officers later asked him if he had any CCTV footage, and when he looked back he saw a white car that made two passes, and on the second pass the car stopped and someone opened the boot.
"I saw the police cars racing down here," he said.
"There was a lot of shouting.
"I thought it was an altercation or something. Then I saw the armed police.
"They were shouting something to the homeowners. That was it.
"I stood in the window watching."
Mr Murray said there were two cars with "three or four" officers in each, "all armed and with their headgear".
"Earlier on there was another policeman with a torch," he said.
"My son said he heard some bangs but I don't know if that was the car doors slamming.
"There was a white hatchback which came around and stopped outside, then about half an hour later he came back and lifted up the boot."
Mr Murray said the footage was "a bit fuzzy, it was dark".
He said this happened at about 9.30pm.
Mr Murray said the car "came around twice", and when someone opened the boot he "couldn't see him get anything out, it was very fuzzy".
He said he does not know if the homes sealed off by police are rental properties but believes "a guy on his own" stays there.
Sarah Lown, who also lives nearby, said she heard three loud bangs on Wednesday evening.
"I didn't know it was gunshots at the time," the 38-year-old designer said.
"It was about 9.15pm; I thought it was something blowing over as I heard a bang.
"There are pallets in our garden that I thought could have fallen over.
"I didn't think anything crazy had happened.
"I heard two more - it was bang, space, bang.
"Whether or not they were each gunshots I don't know; then police were outside the house."
Ms Lown said there were no sirens, "just the flashing lights".
She said a man who lived at one of the properties sealed off by police "always had really fancy cars out the front, souped up, cool looking cars".
"I don't know if he worked with cars," she said. "I had never met him so I don't know."
Forensic officers in white suits worked at the scene on Thursday morning, with two bunches of flowers left on the drive and uniformed officers and a marked car beside blue-and-white police tape sealing off the homes.
Police said they are not in a position to name either victim because formal identification has not been carried out.
Detective Inspector Mark Butler from the major crime unit said police were investigating
"We have launched two linked murder investigations following the shootings of two men at separate properties in the county.
"These events will be shocking to local people and there will be understandable concerns within local communities, however, we are treating the attacks as targeted and there is no wider risk to the general public."
