FORT RECOVERY — State and local investigators continue to make progress in the joint effort to bring the killers of an elderly Fort Recovery man and his caretaker daughter to justice, Mercer County Sheriff Jeff Grey said Wednesday.Cassandra Grube found her father-in-law, Robert Grube, 70, and sister-in-law, Colleen Grube, 47, bound and shot to death inside their rural Fort Recovery home Nov. 30. Since then, investigators from the Sheriff’s Office and the Ohio Bureau of Criminal Identification and Investigation have worked to collect every piece of evidence and talk to as many people as possible to solve the double murder, Grey said.“Murder has no statute of limitations, so we are gathering everything possible to help solve the crime now, in the event it is not solved in the immediate future, we need to have all the information to be utilized later,” Grey said. “It is important to solve this case, but we have to ensure that we get it right. It is important to make an arrest, but we must be able to get a conviction, and we have to be absolutely certain we have the right offenders.”Grey has said previously that Colleen Grube was last seen alive shortly after 5 p.m. Nov. 29. Investigators have narrowed the time of the double murder to a two-hour window and have determined that at least one male and one female were present at the time. Investigators have also said that a laptop computer is missing from the scene, 2216 Burrville Road, in a rural area just east of Fort Recovery.So far, investigators have interviewed more than 90 people, followed up on 73 leads, issued 63 court orders and subpoenas and served 11 search warrants, Grey said.The intense investigative effort has also turned up information on other crimes, Grey said. Information turned up in the investigation helped recover a stolen vehicle in Mendon and bust a methamphetamine lab in Darke County, Grey said. Investigators have not turned up any information connecting either of those incidents to the Grube case.“We have not made a connection. The information just came up during the investigation so we passed it along,” Grey said. “At this point, it is two completely separate cases, just the information came out during our investigation.”You can comment on this story online at www.limaohio.com.