ACCORDING TO RUMORS rolling around the Roundhouse (Philadelphia Police headquarters) these veteran cops could be in the running - some more so than others - to be the next police commissioner.

IN-HOUSE CANDIDATES

Deputy Commissioner Richard Ross, 51, is widely viewed as Police Commissioner Charles Ramsey's logical successor. It's a role many cops believe he's been groomed for since 2005, when then-Commissioner Sylvester Johnson promoted Ross from captain of the Homicide Unit to a deputy commissioner. Ross, often described by his peers as cerebral and articulate, as Ramsey's second-in-command has been in charge of running day-to-day operations whenever Ramsey is out of town. That has been frequent during Mayor Nutter's second term, because of obligations like President Obama's Task Force on 21st Century Policing. Ross is a 26-year veteran of the force who has also worked in Internal Affairs, the Major Crimes Unit and Olney's 35th District.

Deputy Commissioner Kevin Bethel, 51, is mentioned almost as often as Ross in speculative conversations about the next commissioner. Ramsey promoted Bethel from the captain of Point Breeze's 17th District to deputy commissioner in 2008. He oversees patrol operations and detective units across the city, and was in charge of Operation Pressure Point, a crime-fighting effort that had 16 law-enforcement agencies flood the city's most violent districts during the spring, summer and fall early in Ramsey's tenure. Bethel's prior assignments included Internal Affairs, Narcotics Field Unit and the Special Investigative Bureau.

Chief Inspector Joseph Sullivan, 52, is probably instantly recognizable to anyone who's attended the large protests - from Occupy Philadelphia to those in response to the deaths of Michael Brown in Ferguson, Mo., and Brandon Tate-Brown in Mayfair - that have unfolded in the city during the past few years. Sullivan, who oversees Homeland Security, SWAT and Civil Affairs, is always in the thick of the protests, communicating with activists to keep marches from veering into chaos. The 33-year veteran of the force had previous assignments in the Northwest Detective Division, Narcotics and Spring Garden's 9th District.

OUTSIDE CANDIDATES

SEPTA Transit Police Chief Tom Nestel III, 53, is one of the best-known faces of law enforcement in the city, thanks in part to his ubiquitous presence on Twitter, where he uses good humor to mix it up with just about anybody - transit riders, anti-police activists, fellow cops and reporters. Nestel spent 22 years in the Philadelphia Police Department, rising to the rank of staff inspector, before leaving in 2008 to become Upper Moreland Township's police chief. He returned in 2012 to run SEPTA's police force. His father, Tom Nestel II, was a deputy police commissioner in Philadelphia.

Radnor Township Police Chief Bill Colarulo, 56, spent 30 years in the Philadelphia Police Department, reaching the rank of chief inspector, before leaving in 2011 to take the Radnor job. During his Philly tenure, he oversaw the Police Academy, Internal Affairs and the Homicide Unit and served as the department's spokesman.

Daytona Beach, Fla., Police Chief Michael Chitwood Jr., 51, left the Philadelphia Police Department after a 17-year career to run the Shawnee, Okla., department in 2005. A year later, he took over the top cop's job in Daytona Beach. Like his father, Upper Darby Police Superintendent Mike Chitwood Sr., he is known for making headlines with off-the-cuff remarks that usually involve the word "scumbag." During his time in Philly, he served as a lieutenant in the Homicide Unit and Southwest Detectives.

-David Gambacorta