The parallels between the troubled Annapolis and Baltimore City police departments are striking. Both have been caldrons of discontent for the past decade. They share a high attrition rate, frustrations about pay, benefits and slow promotions.

Both Annapolis and Baltimore City recently also got new police chiefs. They have started off in a somewhat similar fashion, aggressively reorganizing and renewing their departments.

Because former Annapolis Chief Harold Robbins, who quit in April, draws his $72,000-a-year salary until his term ends in December, his successor, Col. Joseph S. Johnson, carries the title of acting chief. If such a rank suggests tentativeness, nothing else in Colonel Johnson's manner does. No sooner had he inherited the embattled department than he made sure everyone knew he was in charge.

He streamlined the top command, saying he plans to have no deputy chief but two majors overseeing the divisions. For the time being, however, those divisions are reporting directly to Colonel Johnson, who has reassigned several commanders to instill energy and change in the department.

The reaction, so far, has been favorable. "I've heard nothing but accolades about the man," said Alderman Theresa DeGraff, who heads the City Council's public safety committee.

Colonel Johnson is the first African-American to head the Annapolis force, which has an authorized level of 121 officers. Because of morale problems and political bickering, that strength has seldom been achieved in recent years. Colonel Johnson pledges that improving morale will be his top priority. He also promises to address the explosive promotion issue, which has cleaved the department's white and black officers.

During his rocky tenure, Chief Robbins tried to promote minorities; when he arrived, all 10 corporals within the department were white men. But 13 officers, including Mayor Alfred A. Hopkins' son-in-law, successfully sued the city, contending the stipulations about merit-based promotions had been violated. "I'll level the playing field," Colonel Johnson promises, "but everyone is going to take the same tests."

We like Colonel Johnson's performance so far. His resoluteness and striving for fair play are promising signs.