Four students were found smashing a parking meter on the corner of Bow and Plympton streets at 3:24 a.m. two Fridays ago.

Although both Harvard University and Cambridge police officers were on the scene, it was Cambridge police who made the arrest.

"We could have made the arrest," Harvard University Police Department (HUPD) Chief Francis D. "Bud" Riley said. "But we left it to the CPD [Cambridge Police Department]."

The episode offered a glimpse into the type of relationship HUPD shares with its fellow police departments, including CPD, the Boston Police Department (BPD) and the Massachusetts State Police.

It is a relationship police officers from all forces hail as overlapping but non-intrusive. While there were some jurisdictional quarrels in years past, the relationship among the departments today is amiable.

They get along despite a complex and confusing set of jurisdictional guidelines that would seem to offer ample opportunity for a battle over egos and space.

But officers with HUPD insist that one thing remains simple: the safety of the student body is the No. 1 priority.

Overlapping Powers

Riley said that under Code 22c of Section 63 of the Massachusetts Commonwealth Statute Law, HUPD officers have the same powers as all other police officers.

These powers include the ability to arrest offenders in Suffolk and Middlesex counties, which includes Cambridge and its surrounding environs, HUPD spokesperson Peggy A. McNamara said.

HUPD has primary response jurisdiction over all property owned by the University, and CPD has secondary response powers, she said.

This means that HUPD immediately responds to all campus incidents, and CPD usually responds shortly after, either at the behest of HUPD or in response to calls by observant Cantabrigians.

"CPD and HUPD both arrive on the scene, [and] then we work out the jurisdictional stuff afterwards," Riley said.

If it is strictly a Harvard matter, McNamara said, follow-up is usually contained to the HUPD because CPD defers to HUPD over matters involving Harvard affiliates or Harvard property.

One exception in the law involves the illegal parking of cars within 10 feet of a fire hydrant on Harvard property. In such cases, CPD spokesperson Frank T. Pasquerello said, CPD officers are allowed to "tow and give tickets on any property in Cambridge."