For those that work in the criminal justice system, the tools they use to investigate and solve crimes are critical to their success in prosecuting offenders.  When given the job of searching for important evidence, one of the most important tools used by law enforcement and public safety divers is the underwater metal detector.  These super sensitive detectors routinely help recover weapons used in the commission of a crime, and have been directly responsible for putting many criminals behind bars. 

When a 55 year old woman was murdered in California, members of the Sonoma County Sheriffs Department Violent Crimes Unit quickly learned just how effective underwater metal detectors can be.  The two suspects had allegedly disposed of a knife and gun in a local river, but officers weren’t sure of the exact location.  The department turned to a specialist in the area of underwater search and recovery, Aquatech in Santa Rosa.  The company has all the equipment needed to perform any type of underwater search operation including side scan sonar, sector scanning sonar, and underwater metal detectors.  In addition, the owner of the company, Tom Tessier, had an established reputation for successful recoveries.

Detectives investigating the case had a vague idea where the weapons were probably thrown, which meant a relatively large area would have to be searched.  The conditions at the site were described as, “a tidal river with a foot and half of water at low tide and two feet of silt”, a very difficult environment to locate a weapon.  Mr. Tessier determined that the best piece of equipment for the job was the his JW Fisher Pulse 8X metal detector with boat-deployed 8 by 48 inch oval coil.  Aided by members of the sheriff’s department, a grid pattern was established and the search began.  The coil, which is mounted on four small skis, was carried 100 feet out into the river (the length of the coil’s electrical cable), and then pulled back to shore.  With each pass, the coil would cover more than a 4 foot detection swath along its path.  In less than two hours a handgun was located.  Everyone involved was very pleased with how smoothly the operation had run and how quickly the weapon was located.  However, ballistics testing of the gun proved it was not the weapon used in this homicide.  The team then returned to the river more determined than ever to locate the weapons.   Expanding the search area and using the same techniques that were successful in the first operation, it wasn’t long before the detector gave two strong signals.  Groping in the soft mud where the readings were strongest, sheriff’s department deputies recovered a handgun and a knife.  Tests on these weapons confirmed they were the ones used in the commission of the murder and the suspects are now awaiting trial.  Investigations are continuing on the first handgun that was recovered.

For more information on Fishers complete line of underwater search equipment go to www.jwfishers.com.  For more information on Aqua Tech Search and Recovery go to www.aqua-tech.us.