Poppy Montgomery Welcomes a Boy

FRIDAY JANUARY 04, 2008 04:10 PM EST

Without a Trace actress Poppy Montgomery and her boyfriend, actor Adam Kaufman, welcomed a son on Dec. 23, the star's rep confirms to PEOPLE.

"Poppy and Adam are over the moon," says the rep.

The couple's son, Jackson Phillip Kaufman, was born in Los Angeles and weighed 7 lbs., 4 oz. It's the first child for the pair, who met more than three years ago in Mexico on the set of the independent film Between.

Montgomery, 35, plays FBI Agent Samantha Spade on the CBS drama. Kaufman has appeared on Law & Order and Dawson's Creek.