Staten Island prosecutors said Monday that Paul Marquez is charged with endangering the welfare of a child and harassment.
Authorities say Marquez had been out with the baby's mother a few times but felt she wasn't paying him enough attention. They say he was angry with her so he posted the ads with photos of her daughter on Craigslist.
The mother notified police after she received a phone call from a person offering to buy the baby.
According to a criminal complaint, Marquez says just he wanted to get back at the woman. He was being held in lieu of $1,000 bail. A call to his attorney wasn't returned.