By George P. Hassett

A Medford man trying to shoplift two swim suits from the TJ Maxx in Assembly Square pulled a knife out and threatened to stab store security guards on Friday, police said.

Darrell Johnson, 29, allegedly stuffed the swim suits into his shorts and tried to flee the store. When security tried to stop him, Johnson allegedly pulled out a black handle knife with a spring loaded release and threatened to stab the loss prevention officer.

Johnson was arrested and charged with armed robbery, carrying a dangerous weapon, assault with a dangerous weapon and warrant charges.