Taking the crime watch online

Hingham and Norwell using e-mail system

At a Hingham Citizens Academy, officer Lisa McCracken shows Bob Gibbs a tool for breaking windshields during emergencies. (Essdras M Suarez/Globe Staff)

The 11-year-old child was bicyling home, but not alone. A middle-aged man in a white Ford Crown Victoria was trailing behind, even detouring in the Hingham High School parking lot to maintain his distance.

But he was being followed, too. A concerned witness to the slow pursuit made a cellphone call to the police. Acting on the tip, officers pulled the man over, checked his license and registration, and discovered he was a Level II sex offender near the end of a 10-year probation.

Police told him to leave town. But a half-hour later, someone else spotted him in another part of town and notified police.

That witness recognized the vehicle because of a new system that allows police and citizens in Hingham to work together. The E-Mail Alert System, or EMAS, lets police notify subscribers of suspicious or dangerous happenings, sometimes moments after an event. The second witness read about the white Ford in an EMAS message that was sent out after the man had been stopped, and she recalled seeing his car a full half-hour after the time of the reported incident.

The program was developed by Constant Contact, a Waltham-based e-mail marketing and online-survey company, and is used in this state only by the Hingham and Norwell police. A clickable icon was placed on both towns' police department websites in March so residents could apply for the new service, which sends free public-safety alerts to subscribers' e-mail addresses at a home computer or mobile device.

To date, nearly 2,000 people have signed on in Hingham, 260 in Norwell.

Speed is one of the system's biggest advantages. Sometimes people are not aware of a crime until it's reported in the local paper, which might take up to a week. That can mean the loss of leads.

Another advantage is that people can apprise the police of their concerns in a way that doesn't bog down the department. With a 911 call, officers have to respond immediately. But e-mails can be sorted through and prioritized before being acted upon, giving people the option of contacting police when they think something is amiss, but not necessarily an emergency.

"Sometimes leads pan out, sometimes they don't," said Norwell Chief of Police Theodore Ross, adding that they are always welcome.

Phil He, a Northeastern University associate professor of criminal justice, said the system means "police are not in the difficult situation of having to check out false alarms" immediately.

He considers EMAS a "high-tech expansion of a neighborhood watch type of program" that can help police accumulate leads, show possible patterns, or even provide details that officers can sort through in order of importance.

A second EMAS has been designed specifically for the four main business areas in Hingham - Derby Street Shoppes, North Hingham, South Hingham, and Hingham Centre. Updates on counterfeiters, shoplifters, and other thieves are sent out so that employees have a description of the specific ruses, and sometimes clear descriptions of the people involved.

The chief of police in Dover, Vt., Robert Edwards, whose force has used EMAS for a decade, can attest to its effectiveness. The service led to the arrest of some locals who had been weaving their cars around a mother driving with her child in a desolate area. Their cars were so close she could not make out their license plates, but was able to report what their vehicles looked like.

"Within four hours of a description going out, we got a tip that led us to the right people," said Edwards.

EMAS is more than an alert system. Also e-mailed are notices informing residents of department programs such as self-defense classes for women and children; calls to join a neighborhood watch program; and warnings about lax habits that encourage burglars, such as leaving laptops or handbags on the front seat of your car or near a first-floor window at home.

The system also offers an invitation to the Citizens Academy Program, where residents learn the ins and outs of police work behind the desk and in the field, such as last month's class in Bare Cove Park, where students watched firefighters use the jaws of life, saw a police canine demonstration, and participated in a mock crime scene investigation.

There is even a Mayberry feel to some of the messages. A request for Hingham volunteers to participate in a mock train crash brought nearly 100 participants, almost twice the number of people needed. And within an hour of an e-mailed request for football cleats for a rival town's team, there were a half-dozen cleats in the lobby, with 60 pairs in all by the end of the week, according to Hingham's deputy chief of police, Brad Durant.

"I'm a big believer in the Mayberry thing," said retired police officer Paul Costello, who designs law enforcement websites, including those for the Hingham and Norwell police. He estimated that Hingham police send out five or six messages a month, while Norwell sends two or three.

"EMAS is kind of friendly so that the experience of communicating with the police is a pleasant one . . . and everybody works better together," said Costello.

"We've been getting a lot of good tips from this," said Durant.

It was, in the end, community involvement that helped Hingham police track the sex offender who had followed the child home. The man, who continued driving around the area after police had told him to leave, returned the next day and was stopped one block from an elementary school, about 15 minutes after students were released for the afternoon.

The man now has to serve two more years of probation, and also must wear an ankle-monitoring device and stay at least 75 feet away from public parks and elementary schools.

To sign up for EMAS or to find out more about the Hingham or Norwell police departments' services, log on to hpd.org or norwellpolice.com.

Correction: Because of reporting errors, a previous version of this article incorrectly described the company that created it. Constant Contact is a Waltham-based e-mail marketing and online-survey company.