CHARLESTON, W.Va. -- The parents of a man who killed two West Virginia State Police troopers say their son struggled with drug abuse for years. Darrell Baber and Diana Baber of Oak Hill tell WOWK-TV that they are heartbroken and sorry for their 22-year-old son Luke's "horrible and unbelievably cowardly" actions. State Police say Luke Baber fatally shot Cpl. Marshall Bailey and Trooper Eric Workman Aug. 28 during a traffic stop near the Wallback exit of Interstate 79 in Roane County. Luke Baber also shot and wounded a Roane County deputy and a tow truck driver before he was killed in a shootout with other officers. "We recognize also, that Luke's mindless and calloused shooting of these four men has caused tremendous pain and suffering for their Families, Friends and coworkers, that will continue to hurt for many years to come," Darrell Baber wrote in a statement given to WOWK. "I know of no words that could express exactly how Diana and I feel about what has occurred. We are extremely angry and saddened by what Luke has done to your loved ones and you."The father said the family requested police and emergency medical assistance for their son several times in recent years. "In every case, responders have been timely, professional, caring, and extremely helpful," Darrell Baber wrote. "We love, respect and honor our wonderful protectors, from Police Officers to Highway Assistance Workers."The letter went on to say that the police officers aren't responsible for Luke Baber's death. "They only shot him, as they should have," the letter read. "What killed Luke was drug abuse." Teachers, counselors, doctors, nurses, friends and relatives worked with Luke Baber over the years with his struggles. "In the end, the effects of drug abuse claimed Luke's life, and shattered the lives of many wonderful, innocent people," Darrell Baber wrote. State Police Superintendent Col. Jay Smithers has said Luke Baber was driving a stolen pickup truck when he was pulled over at the Wallback park and ride. The troopers searched Bailey before handcuffing him and putting him in the back seat of their cruiser but they did not discover the 9 mm handgun he had hidden. Baber's hands were cuffed in front of him, and he slipped out of his handcuffs and shot the officers. The troopers were shot while waiting for a tow truck to arrive to retrieve the pickup truck. When the tow truck arrived, Baber shot the driver, William Massey, in the arm and fled on foot. Massey called for help and dozens of law enforcement officers from several agencies converged on the small asphalt parking lot and began searching for Baber, who had taken Bailey's gun. Sheriff's deputies from Clay and Roane counties encountered Baber in a wooded area not far from the park-and-ride area. They exchanged gunfire with Baber and he died after being shot multiple times. Bailey's funeral was held Sunday. Workman, who died at a hospital on Aug. 31, was buried on Wednesday.