The Vienna Town Council unofficially selected Maj. Donald G. Harper last night as chief of the troubled town police force.

Harper, a Fairfax County police officer who has served as acting chief of the Vienna force since June, will be the third man in 13 months to lead the department if the council, as expected, makes its decision final Monday.

The council set the police chief's initial salary at $38,600, but decided to raise the position's designated grade so that Harper will receive quicker raises.

Harper, 42, a 20-veteran of the Fairfax County police force, was commander of its operations support bureau, which oversees the traffic division and units such as special weapons and tactics, the bomb squad, the canine corps and helicopters.

He was named acting chief of the Vienna force June 6 after the Town Council voted to oust Chief Zed L. Childress, who got the job when Chief Vernon L. Jones was fired without explanation nine months before. Since then, Harper has been credited with improving morale in the 33-officer department.

"Major Harper took over under most difficult circumstances," said Mayor Charles A. Robinson Jr. "He improved substantially the morale of the department and got the community's support at the same time. That speaks pretty well of the man."

Childress' dismissal came amid intense infighting in the department. He has since sued the town for reinstatement.

His suit is one of two legal actions against the town. A sergeant still with the department sued the town in June, charging he was wrongly disciplined for an alleged "verbal indiscretion" during an investigation of a shooting incident in January. Another four lawsuits brought by current and former officers of the department against each other are pending in Fairfax County Circuit Court.

Town officials say the lawsuits cast a shadow over the department and undermine its credibility.

In an interview last night, Harper said the infighting and suspicion in the department have started to abate "but there's a long way to go. It'll take time to heal. Once the suits are settled, that'll be the real turning point."

He said he intends to stay on as chief of police in Vienna "as long as I feel I'm needed and I'm contributing."

"There are a lot of changes that need to be made," he said, to make the department "more professional." Specifically, he said the department needs to computerize its records.

Council members said at a work session to choose a new chief last night that many other applicants for the job had more extensive qualifications on paper than Harper. But with little dissent, they agreed that Harper's personal qualities were well suited to Vienna, a bedroom community of 18,000 people.

Before he assumes the Vienna job, Harper must first retire from the Fairfax County force, where he is currently considered on loan to the town.