Murphy said he believed the program's targeting of underage drinking will succeed where similar efforts have failed, because the program is based on a partnership between police, package stores and manufactures.

In the past, the relationship between police and package stores has been an adversarial one, Murphy said.

Package stores that participate in the program do so on a voluntary basis, Scali said.

Currently 32 liquor stores in Cambridge and 14 in Watertown are involved in the program, Scali said.

Massachusetts State Senator Warren E. Tolman (D-Watertown), who also spoke at the news conference, said that the Cops in Shops program is being piloted in Cambridge and Watertown and may be developed across the state "to go at the very root of this problem" of underage drinking.

Nuts and Bolts

More details as to how the Cops in Shops program works were also revealed at Wednesday's press conference.

According to Murphy, undercover police officers may pose as liquor store clerks, shelf stockers or customers.

Murphy said undercover officers are also located outside of liquor stores or in nearby locations and are "alerted to suspicious activity.

The officers stationed outside of the store are also watching to see if people are buying alcohol for minors.

The undercover officers involved in the program are regular patrol officers.

The Cambridge License Commission uses a lottery system to determine which liquor stores will be targeted, Murphy said.

The License Commission then provides the CPD with a sealed envelope containing the name of the establishment to be targeted