"He was starting to enjoy his retirement," said a real estate agent.
The agent, who insisted on speaking anonymously out of fear of retaliation, said she had heard Faull complain about McAfee's numerous dogs barking outside his property.
Other residents said McAfee seemed standoffish and not friendly.
"His physical appearance doesn't really inspire you to go over and make friends with him. He's a little scruffy looking," said another real estate agent, Bob Hamilton.
Martinez said police had questioned other neighbors of Faull but had been unable to locate McAfee.
The AP tried unsuccessfully to contact McAfee by email. McAfee said in May that he was disconnecting his phone because he felt he was being harassed by police.
Police said Faull's computer and phone were missing, but there were no signs of forced entry at his home. Police reported finding a single 9-mm shell casing and said it appeared Faull was killed between late Saturday and Sunday morning, which was a rainy night on the Caribbean island. Faull was last seen at 10 p.m. Saturday.
Associated Press writer Mark Stevenson contributed to this report.