Two brothers suspected of murdering a Washington state couple remained on the loose Monday as authorities continued a frantic hunt to find the dangerous duo.

Brothers John Blaine Reed, 53, and Tony Clyde Reed, 49, may be driving a 2007 Volkswagon EOS Coupes with Washington license plate AXH5106, but authorities, speaking during a Sunday news conference, did not know their current location. Both are convicted felons, though their previous crimes weren't named.

Snohomish County Sheriff Ty Trenary cautioned anyone who sees them to avoid contact.

“They are armed and dangerous and the public should absolutely be worried,” Trenary said Sunday.

Detectives on Saturday found two vehicles – a Jeep Wrangler and a Land Rover – belonging to former Army Airborne Ranger Patrick Shunn, 45, and his wife, Monique Patenaude, 46, in a remote, rocky area about 15 miles from the couple’s Arlington home. Trenary said “it’s clear” Shunn and Patenaude are deceased based on evidence collected from those vehicles, and evidence obtained from the couple’s house. Officials have not yet recovered any bodies.

Trenary said the Reed  brothers were seen on video surveillance disposing of the vehicles that were discovered Saturday.

John Reed’s house was “very close” to where Shunn and Patenaude lived and it’s believed there was a property dispute of some kind between the parties. John Reed had been intermittently visiting his house, officials believe.

It was known that Shunn and Patenaude had been engaged in a legal dispute with neighbors, accusing the neighbors of assault, trespassing and scratching death threats in the mud, The Seattle Times reported. The neighbors were not named in The Times report and it’s unclear if they were John or Tony Reed.

Shunn sought a restraining order against one of the neighbors, but a court commissioner dismissed the request in January, saying a physical encounter between the two groups appeared to be unintentional.

Shunn and Patenaude were last seen Monday and were reported missing Tuesday afternoon. Their disappearance was instantly considered suspicious because it was unusual for the husband and wife to stay out of contact with family or friends for such a prolonged period of time.

“Pat did not show up for work nor did he call in,” Shunn’s brother, Erik Shunn, wrote on Facebook Tuesday. “That is very uncharacteristic of him. Pat and Monique have pets and livestock and they haven’t been taken care of the last day and a half.”