By Tony Gordon Daily Herald Staff Writer ______Toxicology tests on the Lake Zurich couple who died during a police standoff Sept. 16 showed the presence of three different drugs in their bodies, a deputy coroner said Wednesday.Two of the drugs — cocaine and methamphetamine — had to have been ingested during the 16-hour battle of nerves, Deputy Coroner John Rorabeck said.A coroner’s jury ruled the death of Carol Johnson, 53, a homicide, find ing she was shot once in the head by her longtime companion, RobertCC tirkn thnn cHntThe couple had been barricaded in a bedroom of their home at 25226 Ell-rie Road since agents of the Lake County Metropolitan Enforcement Group came to the house the night before the deaths to investigate a report of marijuana plants growing in the backyard.Rorabeck said autopsy results showed levels of cocaine, methamphetamine and marijuana in the blood of both Cooke and Johnson.Given the levels of cocaine and methamphetamine found, Rorabeck said the cocaine would have had to been taken sometime after the siege began around 5 p.m. Sept 15.The methamphetamine could have t.»kpn no longer than four hoursbefore the couple died just after 9 a.m. Sept 16, he said.The methamphetamine was found in levels “which studies have linked to irrational and violent behavior, Rorabeck said.Marijuana also was found in the blood of both, he said, but could have been ingested several days before the standoff Sheriffs Detective Drew Pranke said MEG agents acting on a tip went to the house and found Cooke in the back yard tending to some of 156 marijuana plants, some of which were 10 feet tall.Cooke ran into the house when he saw the agents, Pranke said, and announced he had a weapon andwould kill himself before going to jail.The MEG agents called the sher iffs tactical unit, which negotiated with the couple throughout the night Pranke said.Shortly after 9 a.m., Pranke said, police broke a ledroom window and threw in a canister of pepper spray.“The officers then heard two shots in rapid succession,” Pranke said. “The tactical team entered the house and found both had suffered single handgun wounds to the head. ” Detectives determined Cooke, whose body was found on top of Johnson’s, had shot her in the head and then killed himself with the .38 caliber revolver that was found near his right liand, lYanke said.Report: Couple took drugs before death