On Friday night, in the first few hours of his duty as the acting police chief of Prince George's County, John E. (Jack) McHale was having some trouble with details.

McHale, a close friend and former top aide of County Executive Lawrence Hogan, looked up quizzically as his deputy, Rice Turner, peered in the door before leaving the chief's office at the Forestville police barracks.

"Hey, chief," said Turner."You don't have the keys to this place."

"That's okay," responded McHale, "If something happens, I'm sure I won't be the only one coming in here."

Several minutes later, Turner was again poking his face into McHale's office.

"Hey, chief," he said. "You don't have a badge. There's probably an old chief's badge in the drawers."

McHale thanked his solicitous deputy and went about his business. But, 10 minutes later, there was Turner, standing in the doorway with one more reminder.

"Chief," said Turner, "I was halfway home when I realized that you might not have any car keys."

This time, Turner's good-natured concern was unnecessary. McHale said he had keys to the car, and, after Turner left him alone for good, the new chief relaxed in his chair to watch the television account of his swearing-in cememony. That done, he prepared to go home.

"Got to load up," he said, packing a revolver with several bullets. "Just in case there are any bad men on the way home."

McHale opened his suit jacket to place the gun on his belt. Another surprise was in store.

"Goddamn suit doesn't have a belt," said the chief to himself. He fumbled with his suit and the gun for a time before finally stuffing the weapon into his right pocket, assuring an observer that there was no way it would go off.

With the gun in his pocket and car keys in hand, McHale left the building and strolled toward the police chief's car -- a vehicle that, in his opinion "looks more like a fire chief's car."

Jack McHale, 54, a former FBI man, is the latest in what has become a steady succession of acting police chiefs in Prince George's County since the retirement last summer of former chief John W. Rhoads. His tour of duty is scheduled for 60 days, but all indications are that McHale and his boss, Hogan, would like that to extend into several years.

Although Hogan has not commented publicly on the matter, McHale, according to sources, told a staff of high-ranking police officials during his first day on the job that the county executive wanted him to be the permanent chief.

By McHale's own account, Hogan said to him several weeks ago, after the County Council rejected his first choice for the job, Petersburg, Va., chief James R. Taylor, that the position was his. "Jack," McHale recalled Hogan telling him, "I'm going to send your name down."

Already, Hogan has given McHale the authority to restructure the department's high command, and the acting chief has used that power to name Turner as his deputy chief. That move angered some police officials whose rank was higher than Turner's.

Then, in a related move, McHale returned Joseph Vasco, his predecessor as acting chief, back to his old job as head of the operations division. According to sources, Vasco went along with the move but requested that he be allowed to report directly to McHale.

This request, according to sources, was opposed by Turner, who told McHale that as deputy chief everyone in the department should report to him. McHale agreed with Turner, thus nipping what one police source called an attempted "palace revolt."

McHale, who has never worked for a local police department but spent more than 20 years in the FBI, including a long stint in charge of the organized crime division, said he is confident that his performance as acting chief will be successful.

"The only thing that could scuttle my position is something no one could plan," he said.

"Like I'm home in bed and some off-duty officer goes berserk and kills three blacks.

"But I don't figure I'll put my decorations in here (his office) until I'm permanent. If I put in the drapes, someone might think it looked a little presumptuous."