Coronado police were called to a three-condo structure at 1020 Park Place at about 2:20 a.m. to investigate a report of shots fired at the residence, according to sheriff's Lt. Larry Nesbit.Officers arrived to find an adult male victim, with an apparent gunshot wound, lying in the doorway of the building, said Nesbit."Officers confirmed he had no signs of life," Nesbit said.Officers attempted to make contact with anyone inside the condo, but were unsuccessful, Nesbit said.The small Coronado police department called in a sheriff's SWAT team, which used a robot to enter the building in case an active shooter remained inside. The robot searched the first floor and SWAT team members then entered and searched the second and third floors of the residence, Nesbit said.The bodies of two men and a woman were found inside, Nesbit said. He would not disclose the exact location inside the structure where the additional victims were found or if a weapon had been found. It was unclear if there was a single weapon or if gunfire was exchanged.Nesbit did not elaborate on the circumstances surrounding the deaths, but a source told 10News that all four had been shot. Sheriff's homicide detectives said there was no person being sought in connection with the deaths."Although we are early into the investigation, we do not believe we have any outstanding suspects," Nesbit said.The Coronado Police Department, Naval Criminal Investigative Services, the sheriff's Homicide Detail and sheriff's Crime Lab were participating in the investigation.10News learned Sunday 25-year-old David Reis and his sister, 24-year-old Karen, were two of the 4 victims. David was an F-18 pilot, Karen was a former womens volleyball player from UCSD.The siblings' father Tom Reis said Karen coached volleyball and was thrilled to have her brother move into the Coronado condo. He said they were both in the condo and were both killed. "We don't know the circumstances," said Tom Reis. "We don't know what happened. We only know that they're no longer with us." Sources told 10News the siblings were at a bar in downtown San Diego when they met someone new and brought him back to the condo. The three were believed to be partying with another roommate. Sources told 10News the third victim was roommate Bob Reeves, who was also a Navy pilot. The fourth victim, a 31-year-old man from Chula Vista, was also killed. His involvement with the other three is unclear. On Monday the medical examiner confirmed that two of the people killed were in the military and the ages of those killed were 24, 25, 25, and 31."This is very shocking," said neighbor Julie Lisne. "We think we live in such a safe little town so it's always shocking and sad." Former Navy pilot Don Hubbard lives in the house right next door to the condo where the four people were killed. He said woke early New Years morning to gunfire. He heard a total of seven shots, which sounded like they came from a .45. "There were two shots about a five-second pause and then five more," said Hubbard. He told 10News he liked to talk to the young Navy pilots who lived at the condo. "You know, we talked airplanes, and I didn't get into their family life," he said. Hubbard said David Reis moved in over the summer. The second pilot who was killed had only lived there a couple of months, Hubbard told 10News. David Reis had just gotten his wings from the Navy. "He was really pleased and proud," said Hubbard. Hubbard showed 10News the spots where SWAT team members took up positions in his backyard, which faces the Coronado condo where the shooting occurred. He told reporters he peppered police with questions. "I was very concerned because here we had a killing in my backyard," said Hubbard. "I asked them and they all seemed to think that it was a murder-suicide." Hubbard said police told him they found the murder weapon. Investigators, however, are not saying who they believe pulled the trigger or what the motive might have been. Hubbard said he has seen a lot of bad things in his life, but most pale in comparison to what occurred next door. "It's insane," he said, shaking his head. "It's absolutely insane These were nice, smart kids. These guys were picked [to be Navy pilots] as the cream and now they're all dead. It's terrible." This is the second high-profile case involving a death in Coronado in the past six months. In July, the body of Rebecca Zahau was found nude, bound and hanging off a balcony at her boyfriend's Coronado mansion, which is only about three blocks away from the condo on Park Place. "The amount of crime happening in Coronado is absolutely unacceptable," said Coronado resident Jerry Toci. He told 10News other residents have already been feeling unsettled about the increase in crime in their area. "This is supposed to be a sleepy little town a quaint little village where people come to sleep, not to party," he said. "That sort of thing is not supposed to happen here -- not supposed to happen anywhere -- but this is the least likely place." Officials obtained a search warrant for the three-condo structure off Orange Avenue in the heart of the island city about 3 p.m. Sunday, Nesbit said.The 1000 block of Park Place was cordoned off from Orange Avenue to Star Park Circle due to the investigation.Late Monday, a young couple placed a vase of flowers at the end of the driveway where the tragedy happened. Its hard," said Coronado resident Linda Haley. "It's hard for Coronado and its hard for the military, and its hard for the families and for the parents, my heart aches for them."