Amid a steadily declining proportion of arrests in homicide cases, the longtime commander of the Philadelphia Police Department's Homicide Unit has been reassigned.

Capt. James Clark, who supervised about 70 detectives responsible for investigating hundreds of killings each year, said Thursday that he had been informed of his transfer Wednesday. He said he believed the transfer happened because the Homicide Unit's clearance rate — the number of cases cleared by arrest or other means — had dipped to 37 percent this year from more than 70 percent earlier in his decade-long tenure.

Clark said he was "extremely proud" of his time in Homicide, crediting investigators there with handling a high-volume, high-profile caseload proficiently.

"I really loved the job," he said. "I loved working with the extremely talented individuals. And quite honestly, I loved serving the city."

Police Commissioner Richard Ross did not respond to requests for comment about Clark's reassignment. Capt. Sekou Kinebrew, a police spokesman, did not address Clark's transfer directly, but he said "the department made several command changes this week, which we do periodically." He did not elaborate.

It was not immediately clear who would replace Clark, who begins next week at a unit that performs background checks on police recruits.

As of Wednesday, the city had recorded 166 homicides, up 22 percent from the same time last year and the highest total through early July since 2012, police statistics show.

Staff Graphic

But more significantly for Clark, the unit's clearance rate has been declining for several years. Last year, the year-end clearance rate was 45.4 percent, the lowest annual figure in at least 15 years, and the fourth consecutive year the rate had declined.

From 2008 to 2013, the unit regularly posted a clearance rate of 70 percent or greater, nearly 10 points higher than the national average.

Some detectives in the unit blame the decline on policies implemented in 2014 by department leaders — including Ross —  that changed the way investigators could handle suspects and witnesses. The rules were designed to protect the civil rights of people questioned by police and to prevent detectives from eliciting false confessions.

Some investigators say the rules made it difficult to compel anyone to provide information to police, and Clark forcefully echoed that sentiment Thursday.

The policies, he said, "have really handcuffed, and made it very, very difficult, for my detectives to do their jobs."

Ross has said repeatedly that the rules are not going away.

The even-keeled Clark has been in the department for nearly 30 years. As the public front man for the Homicide Unit, he often was asked to explain some of the city's most gruesome crimes, from murders of children to killings of police officers.

This spring, Ross added 11 detectives to the Homicide Unit, part of an organizational shakeup that marked the first major personnel moves of his stewardship, which began in January 2016.