Representative Anthony D. Weiner, a Democratic candidate for mayor, pledged yesterday to expand the police force and devote more money and resources to combating crimes ranging from graffiti to terrorism.

Mr. Weiner, outlining his proposals in a speech before 30 people in a Pace University conference room in Lower Manhattan, said that as mayor he would hire nearly 4,000 police officers to bring the force back to the 2001 level of 38,630 officers.

He also vowed to increase the use of DNA testing and force ex-convicts to submit samples in an effort to solve more open cases. Mr. Weiner, who represents parts of Brooklyn and Queens, said a tax he has proposed on millionaires would help pay for his initiatives.

Stu Loeser, a spokesman for Mayor Michael R. Bloomberg's re-election campaign, said the mayor already had an accomplished record, overseeing a drop in crime and establishing counterterrorism programs within the Police Department.

"Weiner has no public safety record to speak of, and his proposals are riddled with exaggerations and misstatements," Mr. Loeser said.