Search for missing boy goes hi-tech
Sheriff’s investigators, 12 Upper Pine Fire responders, and a County Road and Bridge backhoe were at Middle Mountain Campground on the back side of Vallecito reservoir Tuesday in the ongoing search for Dylan Redwine.
It was a follow-up to several days of sonar and cadaver dog searches organized by the Hope for Dylan Redwine organization.
Sheriff’s Office spokesman Dan Bender said from the site Tuesday afternoon, “It’s one of the areas where (search) dogs alerted. It’s right on the shore, and the water level is rising.”
The Tuesday search was on the shore and just off-shore. Upper Pine Fire responders put a cofferdam around the location and pumped water out, Bender said.
The backhoe was in case any tree stumps needed to be removed, he said.
Dog alerts prompted this search, he said. Dogs have given alerts at various places that investigators have followed up on since Dylan disappeared.
“What we’re doing this afternoon is just part of our ongoing investigation,” Bender said. Investigators are going door to door again looking for information.
“We’ve never stopped looking for Dylan, even over the winter,” Bender said. Investigators followed up on tips, sometimes going out on snowshoes.
Denise Hess, who has coordinated much of the civilian search for Dylan since he disappeared in November, told the Times this week that Dylan’s family and the Hope For Dylan Redwine organization spent the better part of this past winter researching the best way to search a lake.
Vallecito’s altitude and depth limits divers to a 20-minute dive time every eight hours, she said. The latest search used a technology called side scan sonar as well as cadaver search dogs.
Hess said a recognized expert in side scan sonar, Gene Ralston, contacted her on Facebook the same day that others recommended that she contact him. That was in March. The lake was still frozen over then.
With the lake now ice free, the sonar search started last Friday and continued to Tuesday afternoon, Hess said. Dog searches also resumed in conjunction with the sonar searches.
Hess said Hope for Dylan Redwine contacted the cadaver dog team best suited for their needs and flew in a handler and her dog that is specifically trained and certified on cadavers, but especially recognizes the scent of human remains on water.
The canine team arrived Tuesday, April 16, and with the assistance of a boat donated by Doc’s Marina began searching Vallecito lake last Wednesday morning. The dog began indicating in areas along the mid eastern side of the lake in the water and the shoreline, Hess said.
The team also indicated in areas along the southeastern shoreline and light indication at the dam in the area that teams had indicated last November in the first searches for Dylan.
Last Thursday, the dog team spent the day on the water in an attempt to narrow down the indications in relation to the winds that were blowing, and rule out any other areas of the lake that might indicate a human remains odor, Hess said.
Last Friday, the Illinois canine team did one final check on the very south side of the dam in the waters that come out of the power plant, and the dog indicated that a human remains odor was present, Hess said.
Local resident Roy Vreeland’s dog searched the same stretch of shore, and again the dog indicated the odor of human remains, Hess said. Vreeland and his dog also helped with the early search in November.
Also last Friday, Ralston, his wife Sandy and a third member of their team arrived in the early hours and began the process of getting their boat cleared to place on the lake.
The sonar team was able to spend a few hours on the lake before high winds made things difficult.
Last Saturday the sonar team was able to spend most of the day on the lake scanning the lake bottom in the areas that the canine team indicated. To accurately scan the lake bottom, the boat must move at a speed of about three to five miles per hour in tight grids.
Sunday the team was able to get on the water fairly early and spent a large portion of the day scanning near the dam. Hess said the scan picked up something odd on top of the grate that covers the drain for the power plant.
Also on Sunday, law enforcement brought a helicopter from San Juan County, N.M. that flew low over the lake for about an hour. Right now the lake water is low and clear, Hess said. They didn’t spot anything.
Monday after reviewing the photos of the scans from Sunday, Hess said it was decided that the sonar team would put the ROV (remotely operated vehicle) in the water to see what was on the grate. The ROV equipped with a video camera was launched in the southwest corner of the dam and descended nearly 60 feet to the drain where it discovered large logs, sticks and rocks atop the grate.
The team spent the remainder of the day on the mid eastern portion of the lake that the dogs had highly indicated on, Hess said.
On Tuesday after checking the shoreline where the dogs had indicated “hard hits,” law enforcement representatives decided to excavate a portion of the shoreline to make sure something wasn’t buried.
They began building the coffer dam and the sonar team did additional scans on the water from east to west in that area of the lake before high winds once again drove them back to the marina.
Hess said law enforcement continued digging on Wednesday but apparently didn’t find anything.
Hess told the Times that even though the effort didn’t find anything, “We aren’t disappointed in the work that was done at all. We know there’s a body in the lake (not necessarily Dylan), somewhere in or around the lake in a water source feeding the lake. I have no doubt after watching that dog (from Illinois) work.”
The dog is trained to respond only to cadaver scent, and she gets very excited, Hess said.
Hope for Dylan Redwine funds paid travel, food, lodging, and other expenses for the visiting sonar and dog search teams. They donated their labor, Hess said.
Dylan flew into Durango-La Plata County Airport the evening of Nov. 18, 2012, for a court ordered Thanksgiving visit with his father, Mark Redwine, who lives north of Vallecito.
Dylan was reported missing by his mother, Elaine, in late afternoon of Nov. 19 after a message from Mark asking if she had heard from Dylan.
Mark reported that he last saw Dylan asleep on the couch at 7:30 that morning, and that Dylan was gone in late morning when Mark returned from doing errands in town.
Dylan had been a student at Bayfield Mid School. He moved last summer with his mother to Monument, north of Colorado Springs.
His disappearance brought massive searches by community volunteers. Fundraisers here and in Monument brought a reward fund to more than $50,000. Dylan’s 14th birthday was in February.
Side scan sonar explained
Denise Hess said that Gene Ralston, an environmental consultant who specializes in water related environmental issues, has frequently volunteered his equipment and time to assist the Idaho Mountain Search and Rescue Unit, local and national authorities in searching for drowning victims.
In early 1999, Ralston had the opportunity to experience the successful use of side scan sonar to search for a drowning victim, Hess said. Recently, side scan sonar systems have been developed using medical ultrasound technology to dramatically increase resolution of targets such as drowning victims.
The technology makes it possible to search for drowning victims and other objects under water, including being able to search a large area quickly and safely. Divers are not placed at risk during the search operation and are only deployed for the recovery once the object is found. Side scan sonar images also are useful to evaluate any hazards to divers before they enter the water.
Hess explained that the side scan sonar system's transducer is housed in a “towfish,” which is towed through the water a few feet above the bottom. The reflected acoustic returns are processed into an image similar to an aerial photograph, which is viewed real-time on a computer monitor in the towing vessel.
Typically, the side scan sonar searches a swath 60 to 160 feet wide at about two miles per hour, although other ranges can be used depending upon the size of the object being sought, Hess said.
In the cases where the last location of the drowning victim or homicide victim is not known, Ralston recommends the use of cadaver dogs to locate the scent of human remains on the water. Ralston recommended a few trusted canine teams that he has worked with in the past.