BY SHANE DIXON KAVANAUGH AND JIM RYAN

Updated 9:25 p.m.

Two bridges. Two bodies. One suspect.

Police early Tuesday arrested 26-year-old James J. Barquet, who's accused of fatally shooting two apparent strangers during separate downtown Portland incidents.

The killings occurred four hours apart and less than a mile from each other. In between, investigators say Barquet walked into a gas station with a gun and walked out with cigarettes.

Authorities said Carol L. Horner, 70, of Portland, was shot around 9:05 p.m. Monday and found on the sidewalk along Southwest First Avenue near Harvey Milk Street under the Morrison Bridge. Brian E. Hansen, 51, of Vancouver was shot midspan on the Burnside Bridge's south sidewalk around 12:30 a.m.

Police provided no motive for the killings Tuesday. Barquet is scheduled to appear in Multnomah County Circuit Court on Wednesday.

A small homeless encampment stood near the scene of the shooting beneath the Morrison Bridge, said Sgt. Chris Burley, a Portland police spokesman.

Investigators were able to use surveillance video to identify Barquet in the second killing, Burley said.

Police found the man near Southwest 3rd Avenue and Pine Street about 3:30 a.m. and arrested him without incident, according to authorities.

While in custody, detectives investigating an armed robbery at a Chevron gas station on West Burnside Street determined Barquet was also the suspect in that incident, Burley said.

Police say he brandished a handgun, demanded cigarettes and left the gas station about 10:45 p.m., less than two hours after the first killing beneath the Morrison Bridge.

Homicide investigators in the Morrison Bridge case later identified Barquet as their shooting suspect as well.

Go to our Facebook page, below, to see a 360-degree view of the scene at the bridge.

A woman was found fatally shot under the Morrison Bridge in downtown Portland Monday. The shooting was reported about... Posted by The Oregonian on Tuesday, November 20, 2018

Burley, the police spokesman, said investigators don't believe Barquet knew either of the people fatally shot. Nor was he known to Portland police prior to the killings, Burley said.

He's accused of two counts of aggravated murder, a single count of first-degree robbery and four counts of felon in possession of a firearm, according to jail records.

Public records indicate Barquet has a long criminal history in Washington, which includes charges of drug possession, theft, robbery, domestic violence and unlawful firearms possession.

He has no prior criminal history in Oregon, court records show.

The Oregonian/OregonLive's Everton Bailey, Jr. contributed to this report.

-- Shane Dixon Kavanaugh and Jim Ryan

skavanaugh@oregonian.com; jryan@oregonian.com