Colarulo, 52, who rose from patrol work in 1981, joins a mini-exodus of top brass leaving the rough-and-tumble of Philadelphia for the sleepy world of suburban command.
The trend isn't new. In 1983 Mike Chitwood helped start the flow, leaving a 29-year career in Philadelphia to become chief in Middletown, Bucks County. He detoured to Portland, Maine, and has since returned to the region to lead Upper Darby's department.
Now, there are former Philadelphia police officials serving as top commanders in municipalities from New Jersey to central Pennsylvania. When Colarulo makes the switch March 14, he will make it an even dozen.
The chiefs: John Theobald in East Coventry; Eugene Dooley in East Whiteland; Brian Craig in Swarthmore; Michael Sinclair in West Conshohocken; Thomas Nestel III in Upper Moreland; John Norris in Cheltenham; Keith Sadler in Lancaster City; Richard Wiley in Lower Swatara; Dominick Bellizzie in Solebury; Kenneth Coluzzi in Lower Makefield; and Benjamin Braxton in Willingboro.
The jobs are attractive to Philadelphia police who dream of becoming police commissioner but find that path blocked. Suburban departments offer them a substitute career move.
The money can be surprisingly good: Colarulo will earn $150,000 a year in Radnor, a bump from his $133,755 city salary. Others earn in the low six figures.
And the average Philadelphia commander leaves the city department with enough time in hand to draw a pension, making even a lesser-paying suburban post seem lucrative.
"The jobs are close to home, they pay well and have great benefits," Chitwood says. "It gives you an opportunity to apply the experience and skills you have learned on the job."
In 2007, Nestel had 22 years in, and had risen to staff inspector, when he saw an ad for a police chief job in Upper Moreland.
A fourth-generation officer, he jumped at the chance to have a more grassroots work life.