AKRON (AP) - An investigation of the Akron Police Department will seek to determine why some of the city's police officers have become criminals and why morale is low on the 468-member force.

In the last 18 months, a deputy chief was convicted of theft and a captain was convicted of murder.

A former lieutenant and an honored sergeant were indicted as the result of a raid on a prostitution ring.

Several other officers have retired while under investigation of allegations ranging from sexual harassment to viewing pornography.

An officer was suspended last year for circulating an allegedly racist newsletter in the department.

Recently, an officer tested positive for marijuana and was fired.

''This is a department that has always taken a lot of pride in itself,'' Akron Mayor Don Plusquellic said.

But Plusquellic acknowledged that there is a problem.

As a result, he and Chief Edward Irvine announced Friday the department will be evaluated by a team made up of Akron police officers and a group of experts from the Alexandria, Va.-based International Association of Chiefs of Police.

''I recognize there is a special need for this (evaluation) at this time due to the numerous serious disciplinary actions involving members of the Akron police force,'' Plusquellic said.