Prince George's County police detectives say they believe football star Derrick Fenner was not involved in a shooting rampage in May that left one man dead, and prosecutors will decide next week whether to dismiss murder charges against him, sources familiar with the investigation said yesterday.

Fenner, 20, was indicted in June on charges of slaying Marcellus Leach, 19, who died of a gunshot wound to the head, and of attempting to kill a 17-year-old youth during a shooting in a Hyattsville apartment complex. Police have said the shooting occurred as a result of a battle over drug distribution territory.

But yesterday, sources said county detectives have traced Fenner's activities on the day of the shooting and believe he was not present.

"{County} investigators are certain that Fenner was not at the scene of the shooting and was not involved in the shooting," one of the sources said.

Fenner, who attended Oxon Hill High School before going on to star as a running back at the University of North Carolina, also faces drug charges filed against him before the shooting.

Both county and Hyattsville city police have been involved in the investigation into the shooting, which happened May 23 in a courtyard at the Kirkwood Apartments at 2717 Nicholson St.

Hyattsville police issued an arrest warrant for Fenner in June based on information from two witnesses who told Hyattsville detectives that they saw a small group of men -- including Fenner -- carrying handguns enter the apartment complex.

Fenner had information about the shooting, police sources said, and told Hyattsville police what he knew when he returned to Prince George's County from summer school at the University of North Carolina.

Fenner knew of the shooting, the sources said, because a codefendant in the case, Tyrone Davis, 21, of Oxon Hill, is a longtime friend of Fenner's.

Fenner denied he was involved in the shooting, the sources said, but lied to detectives about where he was when the incident occurred. Another source said that Fenner had also persuaded another person to lie about Fenner's whereabouts.

Hyattsville police charged Fenner, and a county grand jury indicted him based on that information and the witnesses' identification.

Hyattsville police discounted Fenner's later alibi because of his earlier lies and because of witnesses' accounts, sources said.

But a county police source said yesterday that Hyattsville detectives did not thoroughly investigate the alibis Fenner had given.

Fred R. Joseph, Fenner's attorney, said that Fenner has maintained his innocence all along. "It looks as though people are now beginning to take him seriously," Joseph said.

County police sources said that the information developed on Fenner -- and their belief that he was not involved in the shooting at Kirkwood Apartments -- does not have anything to do with separate drug and weapons charges pending against him.

Two Hyattsville detectives who investigated the shootings, Sheldon Hayes and David Weir, have recently been reassigned to uniformed patrol duties.

Hyattsville police spokesmen could not be reached for comment yesterday about the county police investigation or whether the detectives' reassignment was related to the Fenner case.

According to court documents, on April 9 in the 5400 block of Kirby Road in Oxon Hill, a county police officer stopped a vehicle Fenner was driving and found 25 plastic bags containing traces of cocaine in his jacket and a .38-caliber handgun under the driver's seat. Charges in that case are pending.

Fenner entered the University of North Carolina in 1985. Last year, he rushed for 328 yards, an Atlantic Coast Conference record, against the University of Virginia, 216 yards against the Citadel and 173 yards against the University of Maryland.

If convicted of all charges in both cases, he would face up to two life sentences plus 47 years and $27,500 in fines, according to the state's attorney's office.