BALTIMORE (AP) _ The family of a slain federal prosecutor said Thursday they are shocked and overwhelmed by the 38-year-old's ``tragic and violent death'' and are cooperating with investigators.

In their first public statement, faxed Thursday to The Associated Press, Jonathan Luna's family said they were not in a position to comment on the investigation.

``Jonathan was a loving, caring and attentive husband and father. He and his wife shared a wonderful life with their two sons,'' the family wrote.

Luna, an assistant U.S. attorney in Baltimore, had 36 stab wounds when he drowned in a Pennsylvania creek last week with his bloodstained car idling nearby.

Investigators said they have found nothing to indicate the crime was connected to any cases he handled, and they have been looking into his private life.

The family said Luna's parents wanted people to know their son was ``a devoted and good son who worked very hard to achieve his professional success.''

Luna lived in Elkridge with his wife, Angela, their two sons, 5-year-old Justin and 10-month-old Jacob, and her mother, Francine.

``We know that all of our family, friends and Jonathan's colleagues share in our deep grief and sadness,'' the family wrote.

Also Thursday, a federal law enforcement official said investigators believe Luna's car was the only one at the crime scene, despite accounts from gas station workers that Luna bought gas for his car and another vehicle the morning he was killed.

``We're about 99 percent sure it's just the one car,'' said the official, who spoke on condition of anonymity.

FBI officials declined to comment on how they think the killer escaped.

Workers at a Sunoco station in King of Prussia, Pa., said Luna bought gas there after 3 a.m. on Dec. 4. His body was discovered at 5:30 a.m. off the Pennsylvania Turnpike in Denver, Pa., about 45 miles west of King of Prussia.

An employee at a rest stop halfway between King of Prussia and the spot where Luna was found said Thursday she saw the prosecutor shortly before he was killed. Kathy Seidel, the overnight manager at a Roy Rogers, said she couldn't tell whether Luna was traveling alone.