Court rules police can immediately act on anonymous 911 tips if they're detailed enough and corroborated with other evidence

The Supreme Judicial Court today upheld a Belmont man's OUI conviction that came about due to an anonymous 911 about a swerving car on Memorial Drive by a state trooper who didn't actually see the swerving.

But in upholding John DePiero's conviction for a 2011 arrest, the state's highest court broke with the US Supreme Court, which ruled in 2014 that anonymous 911 calls are inherently legitimate as tips that can lead to a traffic stop these days because false 911 calls can be tracked. The SJC ruled that, in Massachusetts at least, unless 911 callers are first informed their calls can be tracked, an anonymous caller with malice on his mind might still make that false report if he was unaware he could be tracked.

In DePiero's case, the court ruled, that was not an issue and rejected DePiero's request to overturn his conviction because the 911 call was not enough for the warrantless traffic stop that led to his arrest.

After getting the call, a state trooper was alerted. Rather than try to catch DePiero on Mem Drive, he found his home address and drove there and then waited - and checked DePiero's record, which showed he was on probation for drunk driving.

After DePiero pulled into his driveway, the trooper turned on his blue lights and went to talk to him. "The defendant almost fell on exiting the vehicle," had "wild" hair, smelled of alcohol and failed field sobriety tests, at which point the trooper arrested him and took him to the nearest barracks for booking - and a breath test, on which he blew a 0.18, well above the drunk-driving level - the court said.

Although the court declined a request from Middlesex County prosecutors to adopt the Supreme Court's faith in anonymous 911 calls as being legitimate causes for a stop by themselves, the court upheld DePiero's stop because the caller calmly provided fairly detailed, specific information about DePiero's swerving on a specific road and because the trooper then coupled that by checking DePiero's record and finding the drunk-driving conviction.

We need not decide whether a single instance of erratic driving may not be a crime, because the information provided by the unidentified caller regarding the defendant "swerving all over the road," coupled with the information about the defendant being on probation for a similar crime, was sufficient to create a reasonable suspicion of criminal conduct, permitting [the trooper] to make the stop even without seeing any suspicious behavior personally.