Massachusetts Appeals Court February 6, 1997, No. 96-P-1090 (Commonwealth v. Grassa)

Kaplan, J.

The undisputed material facts are as follows. About 4:00 p.m., May 7, 1994, John Thomas and Winston Harper, plainclothed security guards at the Stop & Shop supermarket in Malden, leaving the store to attend to a case of shoplifting, heard a car alarm go off in a Chevrolet van in the adjacent parking lot.