Source: A Modesto-area cyclist was killed in a collision with a pickup shortly after 7 a.m. Tuesday on Fountain Grove Parkway in Santa Rosa, the fifth death of a bicycle rider in the past 10 weeks on Sonoma County roads. The crash occurred on a steep stretch of the parkway at Thomas Lake Harris Drive, where a dark blue pickup heading uphill turned left into the path of the westbound cyclist, Police Sgt. Rich Celli said. Cyclist Ruben Hernandez, 37, was visiting Sonoma County from the Modesto area, Celli said. The driver of the truck was identified as Adam Bigham, 22, of Sebastopol. Hernandez was wearing the shorts and jersey of typical recreational cyclist and was riding a high-end road bike. He was pronounced dead at the scene. Officers said he was in the right-hand lane and traveling with traffic at a speed that may have been as fast as 40 mph, the speed limit on the lower part of Fountain Grove Parkway almost a mile from Mendocino Avenue. Bingham was heading east in a Chevrolet pickup on the parkway approaching Thomas Lake Harris Drive. “The truck appears to have made a left-hand turn into the path of the cyclist and other traffic,” Celli said. “We are still getting statements from witnesses. There were no skid marks indicating others had to take evasive action.” Celli said the Sonoma County District Attorney’s Office is involved in the investigation and will be responsible for determining whether charges will be filed against Bigham. Police closed westbound lanes of the parkway from Alturia Drive to Thomas Lake Harris Drive after the crash. The collision occurred on a stretch of Fountain Grove Parkway where vehicles and cyclists easily can reach the 40-mph speed limit. Updated Source: Sonoma County District Attorney Jill Ravitch said Thursday that she will not file criminal charges against a 22-year-old Sebastopol man who was involved in a fatal collision with a bicyclist in July. Adam Bigham was headed to his construction job July 31 when Modesto cyclist Ruben Hernandez struck Bigham's pickup on Fountain Grove Parkway in Santa Rosa. Hernandez, a 37-year-old teacher who was attending a conference in Santa Rosa, died at the scene from the injuries he suffered in the 7 a.m. crash. Bigham had turned left in front of Hernandez heading onto Thomas Lake Harris Drive. Witnesses reported his view of Hernandez may have been blocked by another vehicle, Ravitch said. Hernandez also was reported to be "going a pretty swift speed," she said. Ravitch said there was insufficient evidence to charge Bigham with misdemeanor manslaughter, which carries a penalty of up to a year in county jail.