Republican George Bush touted his endorsement by Michael Dukakis' hometown police union Thursday, prompting Dukakis to surround himself with other law officers and accuse his rival of "assault and battery on the truth."

"What George Bush is doing to the truth in this campaign is a crime," the Democratic presidential nominee said in perhaps his strongest attack on Bush to date. "His administration has waged not a war on crime, but a war on crime programs."The sharp rhetoric came three days before Dukakis and Bush were to face each other in the first of their two nationally televised debates - confrontations that both sides consider crucial.

The bipartisan commission on debates announced Thursday that Jim Lehrer of public television's MacNeil/Lehrer NewsHour would be moderator Sunday in Winston-Salem, N.C., and panelists would be Peter Jennings of ABC News, Anne Groer of the Orlando Sentinel and John Mashek of the Atlanta Constitution.

And an NBC News-Wall Street Journal poll released Thursday showed Bush and Dukakis essentially tied, with Bush's 45-41 lead softened by a 2-point margin of error. The lead for Bush was lower than the 47-40 recorded for Bush last month, and the survey of 2,630 likely voters found he had lost support among Reagan Democrats, going from 35 percent to 25 percent.

Furthermore, half the respondents thought Indiana Sen. Dan Quayle was a bad choice to be Bush's running mate.

Meanwhile, President Reagan was back on the campaign trail for his vice president in Texas, scorning "born-again George Pattons" who say they support a strong national defense. It was an apparent reference to Dukakis, who spent last week sounding hawkish as he laid out his defense policies and rode in a modern M-1 tank.

Reagan spoke to students at Baylor University in Waco, then was joining Bush at a big fund-raising dinner in Houston.

Bush traveled to Boston to pick up the endorsement of the Boston Police Patrolmen's Association, a 1,500 member union.

"I'm the one in this race who wants to strengthen law enforcement," declared Bush. "My opponent is strongly out of the American mainstream on issues such as fighting crime."

Although Dukakis has won the backing of other police groups in his state and in Bush's adopted home state of Texas, a spokesman for the Boston police group said its members felt Bush would be more attentive to law enforcement needs than would the Massachusetts governor.

Robert T. Guiney, president of the association, called Dukakis "no friend of police." He cited Dukakis' opposition to the death penalty, his support for a former program granting weekend furloughs for convicted felons, and Dukakis' failure to attend funerals for three police officers recently.

It was not the first time the Boston police union has endorsed a Republican. In 1980 and 1984 the association supported Reagan and in 1984 it endorsed Republican Ray Shamie in his unsuccessful Senate bid against John Kerry.

The visit was Bush's second to Boston as the Republican presidential nominee. Earlier this month he denounced Dukakis for failing to clean up pollution in Boston Harbor.

Dukakis responded a few hours after Bush spoke with a rally of his own on the Massachusetts Statehouse steps. The governor was surrounded by police officers from Massachusetts and eight other states.

He declared Bush a "fugitive from the truth" who has shamelessly portrayed himself as a crimefighter and advocate of the environment, education and elderly.

He was joined by New York Gov. Mario Cuomo, who accused Bush of pandering. "I'm tired of the simplistics and the distortions by people like the vice president," Cuomo said.

Dukakis' counterpunch overshadowed his only previously planned event of the day - an appearance at a senior citizens center where he accused Bush of trying to harm Social Security.

"When election time rolls around, Mr. Bush likes to say he is a great friend of older Americans," Dukakis said. "Maybe he thinks we all have amnesia."