In something of a leadership shake-up, Chester Mayor John Linder has replaced three of his highest level police officers with three formerly lower-ranking lawmen.

In addition, the mayor announced Tuesday that he has created a police narcotics task force and beefed up highway patrol.

Linder, who also is the city's public safety director, said the personnel moves are part of the changes and on-going assessment he vowed when he took office last year.

"I saw some areas I wanted to change, and the only way to change things was to move (personnel) around," Linder said Tuesday.

Asked if the moves were a sign that he was displeased with the three formerly high-ranking officers, Linder said, "I wouldn't say they weren't doing a good job. I was very candid with everyone. I wanted to change things around."

With those changes which went into effect Monday, Capt. Otis Blair was promoted to deputy police commissioner, the department's second in command. Capt. Alan Davis and Sgt. James Collins were both raised to the rank of major.

On the downshift, former police chief Darren Alston, who was demoted to lieutenant colonel of administration after Linder took office, was moved down to captain.

Neither Alston, who had filed a defamation suit against Lender and the city, nor the other affected officers could be reached for comment.

Linder denied that Alston's downgrade had anything to do with the lawsuit.

Maj. Robert Archacki was bucked down to captain and Maj. John Gretsky was moved to sargeant.

Police Commissioner Joseph Bail Jr., who was appointed by Linder, said Archacki and Alston become shift supervisors and Gretsky will chair the newly created narcotics task force.

Bail said the mayor made the final personnel decisions but he and Linder have been in "constant contact."

As part of the deployments, seven officers were assigned full-time to narcotics and highway patrol got an additional officer. Linder said he hopes to add 10 to 15 officers to the force within the year.

Linder's police leadership changes may face a City Council challenge, according one council member.

Councilwoman Portia West said the mayor has the right to hire and fire the police chief or commissioner, but she said her reading of the city's codified ordinance is that a majority vote by the council and the mayor is required for the kinds of personnel changes he single-handedly made last week.

"It's unprecedented," West said of Linder's action.

She added: "We are looking at possible action."

Linder said he believes he had the power to make the changes.

"I'm the mayor," he said. "I run the department."

Contact staff writer Rita Giordano at 610-313-8232, rgiordano@phillynews.com or on Twitter @ritagiordano.