The city is planning to offer a six-figure prize if an inventor can formulate a handheld device that can analyze DNA at crime scenes, Mayor Bloomberg announced yesterday.

“We’ll use the latest technology to continue turning up the heat on criminals — and, to more quickly exonerate the innocent. The single most powerful way to do both is through DNA analysis,” Mr. Bloomberg said.

The prize was announced during the mayor’s State of the City address, as was a broader initiative to press state lawmakers to pass legislation that would require DNA samples be provided by anyone who is arrested.

To win the invention prize — a privately funded pay-out the source of which has not been determined — a scientist will need to develop a platform that is capable of matching at least 13 different genetic traits, the number required to get a conviction. It will also have to fit in a briefcase, handle the wear and tear of daily use in the city, and determine a result within two hours.

There is no technology in the world capable of the city’s specifications, Robert Giles, the executive director of research and development at a company that provides DNA testing services, Orchid Cellmark, said.

‘It’s getting closer, but a lot still needs to be done,” he said.

A Massachusetts-based research company, BioTrove, offers a bench-top system called OpenArray that can produce even more sophisticated results than the 13 markers required by the city. However, it would need to be transported in a van or truck and analysis takes at least 3 1/2 hours. The Bloomberg administration believes that by offering a prize for the technology, instead of sending out a request for proposals, the private sector will be more motivated to cross the finish line, the mayor’s criminal justice coordinator, John Feinblatt, said.

In New York State, DNA samples are collected from criminals convicted of felonies and high-level misdemeanors. Mr. Bloomberg is proposing the state pass legislation that would require suspects arrested for any crime to give law enforcement a DNA sample.

If a collected sample does not match DNA from another crime and the suspect is not convicted, then the DNA would be expunged, Mr. Feinblatt said. Otherwise, it would be kept in a database for investigators, he said.

Legislative attempts to broaden DNA collection in the state have met criticism from civil liberty advocates, so the plan is likely to face roadblocks.

Since the state in 2006 began collecting DNA from criminals convicted of all felonies and high-level misdemeanors, law enforcement in the city has been able to solve 179 crimes unassociated with the conviction.

“Crimes like shoplifting are the ones that violent criminals often commit early in their careers,” the president of the Citizen’s Crime Commission, Richard Aborn, said. “It’s important to get the samples early.”

While only four other states in America have laws that permit law enforcement to collect DNA from convicted felons, Mr. Bloomberg pointed out in his speech that the federal government and a growing number of European countries collect DNA after any arrest.