Federal authorities have new leads in the search for the remains of an Israeli tourist who disappeared in 2003 after he picked up an escaped prisoner who was hitchhiking in Texas. Jonathan Lee Vernier, 36, was convicted Thursday on federal charges of carjacking with intent to cause death or serious bodily harm in the death of Ran Mesika, 22. Vernier admitted in testimony this past week to disposing of the body in Louisiana between Lake Charles and Crowley. Vernier had escaped from a Colorado prison and was hitchhiking along Interstate 10 in Texas when Mesika stopped to give him a ride in April 2003. US Attorney Donald Washington said Friday that investigators are following up on leads that arose during the trial and hope to work with Vernier to locate Mesika's remains. Vernier - who argued self-defense - admitted striking Mesika with a tire iron in the parking lot of a Wal-Mart store in Lake Charles and said he disposed of the body while driving east toward Crowley. Vernier said he could not remember which interstate exit he took or any distinguishing landmarks, however. The US Attorney's Office and the FBI are asking landowners who have property within a few kilometers of I-10 between Lake Charles and Crowley to search their land for clothing and human remains. Washington said federal investigators are wondering whether Vernier knows more details about the location of the body than he has revealed. Vernier might be reticent to speak because of the possibility of additional charges in state court related to the homicide, but he already faces up to life in prison on the federal carjacking charge in connection with Mesika's death. Prosecutors said Vernier struck Mesika after traveling a few days with him and then stole his van. Mesika's family in Israel asked US authorities to investigate after they stopped receiving telephone calls from him. FBI agents tracked transactions with Mesika's stolen bank and credit cards to locate Vernier in Key West, Florida. Vernier has already been sentenced to serve 17 years on federal theft charges in Florida for stealing the van - filled with jewelry Mesika had been selling while traveling across the US - and for making unauthorized withdrawals with Mesika's bank and credit cards. Vernier is set for sentencing August 8 before US District Judge Patricia Minaldi.