He served as a regular columnist for the Long Island newspaper Newsday[3] until his retirement on November 2, 2004, though he still published occasional pieces for the paper until his death.

Breslin and his sister, Deirdre, were raised by their mother, Frances (Curtin), a high school teacher and New York City Welfare Department investigator, during the Great Depression in the United States.

In 1970, he was viciously attacked and brutally beaten at The Suite, a restaurant then owned by Lucchese crime family associate Henry Hill.

The attack was carried out by Irish mobster Jimmy Burke, who objected to an article Breslin had written involving another member of the Lucchese family, Paul Vario.

[22] Two years later, on September 6, 1973, he appeared on The Tonight Show Starring Johnny Carson alongside Glen Campbell, Don Rickles and Dom DeLuise.

In 1977, at the height of the Son of Sam scare in New York City, the killer, later identified as David Berkowitz, addressed letters to Breslin.

[25] In 2008, the Library of America selected one of Breslin's many Son of Sam articles published in the Daily News for inclusion in its two-century retrospective of American true crime writing.

[26] In 1978, Breslin, without significant acting experience, appeared in Joe Brooks' feature film If Ever I See You Again in a main supporting role playing "Mario Marino," the assistant to two Madison Avenue jingle composers.

[34][35] In May 1990, after fellow Newsday columnist Ji-Yeon Yuh described one of his articles as sexist, Breslin heatedly retorted with racial and sexual invective.

[39][40][41] Author and former FBI agent Robert K. Ressler has stated that Breslin "baited Berkowitz and irresponsibly contributed to the continuation of his murders" by trying to sell sensationalist newspapers.

[42] In return for his "relentless columns on police misbehavior," the local patrolmen's union bought protest ads in his own newspaper.