AUBURN — Nine days after a 5-year-old boy fell into the Androscoggin River, search efforts continued Thursday with digital imaging of the river’s depths and banks.

A high-resolution camera captured more than 800 high-resolution pictures of the swollen river, stretching from Bonney Park, where Valerio McFarland was swept downstream on the evening of April 24, to Lisbon Falls.

On Thursday night, retired military analysts from around the country were to piece together the images and inspect them for signs of any colors of clothing worn by the boy that evening, including a yellow undershirt and a light blue-and-white camouflage jacket, according to Richard Bowie, who heads up the Bangor-based Down East Emergency Medicine Institute, or DEEMI, which conducts search, rescue and recovery operations.

The camera was aimed through a Plexiglass window built into the bottom of the fuselage of a Citabria two-seat plane. Pilot Lt. Col. Al Jenkins, retired from the Air National Guard, piloted the plane while volunteer Nancy Staples operated the camera as the plane followed the winding river, first downstream, then back, for the 90-minute, round trip. The camera’s anti-glare filter enabled Staples to penetrate the river’s surface to a depth of 14 feet, Bowie said.

Once all of the images have been uploaded, he said they will be shared with ex-military analysts who performed a similar function while on duty and now volunteer their time for search efforts such as this one.

The science behind the imaging technique is sound and has yielded results, Bowie said.

In 2007, the body of a 3-year-old girl was found by a DEEMI search team at Tinker Dam, a hydroelectric dam near Fort Fairfield, using a similar imaging technique, Bowie said. The toddler had fallen a couple of months earlier into the Aroostook River that flowed past her home in Fairfield, according to published reports.

“That was the first, very effective use of the imaging from the aircraft,” he said.

The body of a 19-year-old college student was recovered from Otter Creek in Middlebury, Vermont, thanks to a DEEMI search using digital imaging. Bowie said the picture showing the teenager’s body in the river was the third taken in a series captured by a camera in a DEEMI plane in April.

The student had been missing since February. The image was analyzed later that day and the information relayed to fire officials, who recovered the student’s body caught up in a logjam downstream from where it was pictured, Bowie said.

“It makes you believe in simple technology working. It really does,” he said.

Each image is tagged with GPS coordinates so that location information can be conveyed directly to ground searchers or divers, Bowie said.

Analysis of the images should be completed Thursday night, said Bowie, who also will be inspecting the pictures.

If the boy’s body is shown in any of the images, “we will know tonight,” he said.

In addition to the search plane’s efforts, DEEMI deployed about a half-dozen pairs of volunteers along the banks of the river Thursday, but moved them into vehicles as lightning moved into the area. They were equipped with binoculars and life jackets, and told to stay at least 20 feet from the water.

Meanwhile, the McFarland family has established a volunteer center for Twin Cities residents who would like to join in the search for Valerio, Bowie said.

The center will be open from 7 a.m. to 5 p.m. Friday at City Cab, 57 Whipple St., Lewiston.

Those interested in volunteering should call Jennifer at 207-689-9916, or go to the center, Bowie said.

All volunteers are required to sign in and out and to search in pairs, said Bowie, who assisted the family with establishing the center.