A 17-year-old Falls Church youth has been arrested and charged with murder in the October 1976 slaying of Ronald J. Pettine, a former Morris K. Udall campaign aide whose nude, battered body was found near the Iwo Jima Memorial in arlington.

U.S. Park Police said yesterday they arrested the youth Friday following an intensive, 16-month investigation by Park Police detectives.

The youth was not identified because of his age. He was held without bond over the weekend in Arlington Jail, according to Park Police, and was arraigned on a murder charge in Arlington on Monday.

The hearing apparently took place in Arlington Juvenile Court which releases no information about the cases it handles. A spokeswoman for the court said yesterday she could not even confirm that the youth ahd appeared before the court.

National Park Service spokesman George Berklacy said U.S. prosecutors have deferred to local authorities in the case. The slaying took place on federal park land within Arlington. The Iwo Jima Marine Memorial, which had been a nighttime crysting spot for homosexuals for several years before Pettine's death, adjoins Arlington National Cemetery.

Park Police declined yesterday to comment further on the case or how they came to arrest the Falls church youth, other than to say as many as five detectives have been working on Pettine's slaying for more than a year.

Police interviewed hundreds of alleged homosexuals who had been arrested on sodomy charges at the memorial during the year preceding Pettine's arrest. A popular tourist spot by hay, the monument had become a rendezvous for homosexuals at night until the slaying. The woohs around the memorial have since been cleared of underbrush and there have been no arrests there since Pettine's slaying Oct. 2, 1976, Park Service spokesman Berklacy said yesterday.

Pettine, 32, who lived in springfield with his wife and two children, was a sometime homosexual, according at least four persons who worked with him during Udall's presidential campaign in early 1976. He directed scheduling and did advance work for Udall in 975 and had been a deputy secretary of state in Pennslvania prior to that.

Pettine was appointments secretary to Pennsylvania Gov. Milton Shapp during his gubernatorial campaign in 1970 and was a campaign aide to Sen. Hubert H. Humphrey during Humphrey's 1966 presidential campaign.

The Falls Church youth is the second person in a year to be charged with murdering Pettine. A 23-year-old a Kansas man was arrested last Feb. 18 after he allegedly approached Richmond policeman and said. "I'm the guy everybody is looking for in the killing of Ronald Pettine."

The charges were dropped five days later after Park Police detectives became convinced he knew nothing about the slaying. The man was ordered by a U.S. magistrate to undergo psychiatric treatment and return with his parents to Kansas City.