( CNN ) -- In the middle of a shooting spree that killed three people and unleashed terror on Southern California motorists Tuesday morning , Ali Syed told one of his carjacking victims to walk away , police say . `` Mr. Syed ... said , ' I do n't want to hurt you , I killed somebody . Today 's my last day . Give me your keys , ' `` Tustin Police Chief Scott Jordan told reporters . According to preliminary accounts from police , Syed , 20 , did n't intentionally spare another target . Police say they believe Syed , a part-time college student , fatally shot a woman at his family 's Ladera Ranch home before killing two other people -- including a senior citizen executed outside his vehicle -- and wounding three others as he fired a shotgun at Orange County motorists on the Costa Mesa Freeway and committed three carjackings . The spree ended when Syed died after he turned his gun on himself as police approached on a road north of Tustin , authorities say . The Orange County Sheriff 's Department says it was called to the Ladera Ranch home , where Syed lived with his parents , on a report of shots fired about 4:45 a.m. PT . A woman in her 20s was found dead there . Police said she was n't related to Syed , but they did n't release her name , and they said they did n't know why she was at the home . Syed left the home in his parents ' SUV , police said . About 25 minutes after that police call and 20 miles to the northwest , Syed drove into a Denny 's and Big Lots parking lot in Tustin , exited the vehicle and shot a driver in the back of the head , Jordan said . The wounded motorist -- a man who was waiting for his son to carpool with him to work -- managed to drive away before stopping near an overpass , Jordan said . The victim was being treated Tuesday , police said . That 's when Syed , whose SUV had a flat tire , approached the man he would spare . Syed ran toward the man at a nearby gas station , took his keys and drove the pickup truck away without firing at him , Jordan said . Syed then drove south on the Costa Mesa Freeway , exited onto a transition road , got out of the vehicle and fired a shotgun at southbound vehicles on the freeway , hitting three vehicles , police said . One of the freeway drivers was wounded in the hand and face , but investigators do n't know whether the wounds were from shotgun rounds or debris , according to Jordan . Police said Syed then drove to nearby Santa Ana , crashing the pickup into a curb on a freeway off-ramp . There , he pointed the shotgun at Melvin L. Edwards , 69 , of Laguna Hills , who was in a BMW at a stop sign . `` Syed ... got ( Edwards ) out of the car at gunpoint , walked him across the road and executed him -- shot him three times , '' Jordan said . Syed drove Edwards ' BMW to the parking lot of a Tustin-area Micro Center computer store , where police said he found his next two shooting victims . Syed shot and killed Jeremy Lewis , 26 , of Fullerton , who was in a vehicle in the lot , police said . Lewis had worked at a construction site across the street . People from the construction site then approached , and Syed shot and wounded one of them in the arm , Jordan said . Syed entered that person 's vehicle and drove north on the Costa Mesa Freeway before exiting again . By that time , authorities had received many phone calls about the shootings , and California Highway Patrol officers found Syed driving at an intersection about 5 miles north of Tustin , Jordan said . Syed exited the vehicle as it slowly rolled near the intersection , according to police . `` There really was n't a confrontation at that very end , '' Jordan said . `` As soon as he got out of his vehicle , before it actually came to a complete stop , he shot and killed himself , '' Jordan said . Syed was unemployed and taking one class at Saddleback College in Mission Viejo , an Orange County Sheriff 's Department spokesman said . Police said they 're trying to determine what led to the shootings , and that they did n't yet know of a motive . CNN 's John Fricke contributed to this report .
Ali Syed killed three , wounded three during spree that involved carjackings in Orange County , police say . Authorities : Syed first killed woman at his parents ' home , then shot at motorists . Suspect killed himself after police spotted him north of Tustin , police say .