The D.C. Board of Elections and Ethics is issuing subpoenas for more than 70 city residents, who circulated petitions to put the legalization of slot machines on the Nov. 2 ballot, as part of an investigation into allegations that they forged signatures, falsified addresses and committed other violations of election laws.

Attorneys for the elections board said yesterday they have successfully served 11 circulators. But a large number have not been found at addresses listed as their homes, including several homeless shelters. The first group of circulators is scheduled to testify before the board today.

The subpoenas are being issued in response to two formal challenges to the slots campaign, which gathered 56,044 signatures on 3,867 forms during a five-day period that ended July 6. Elections board Executive Director Alice P. Miller called the number of signatures submitted unprecedented. The slots initiative seeks voter approval for a plan to open a gambling hall with 3,500 slot machines at New York Avenue and Bladensburg Road NE.

Slots supporters said at least 17,599 were the valid signatures of registered D.C. voters, enough to place the initiative on the ballot. But this week, a lawyer and a team of community activists challenged hundreds of petitions, claiming that dozens of petition circulators lied on affidavits attesting that they were D.C. residents and that they were in the presence of every person who signed the petition forms.

The challenges, filed by lawyer Ronald L. Drake and a coalition of anti-slots activists led by DCWatch Executive Director Dorothy Brizill, charge that many petitions were circulated by an army of out-of-town professionals, who paid or duped D.C. residents into signing the affidavits or forged signatures on the forms. Submitting a false affidavit is punishable by up to a year in jail and as much as $10,000 in fines.

Yesterday, Drake and Brizill asked the board to bar the slots initiative from moving forward, saying they had found "a pervasive pattern of fraud and forgery," as Brizill put it.

"If the circulators lack integrity, they have polluted the whole process," Drake said.

Former D.C. Council member John Ray, who serves as general counsel for the slots initiative, countered that slots supporters and the California firm they hired to manage the petition drive did their best to ensure that petitions were circulated exclusively by D.C. residents. The circulators, who were paid as much as $6.50 per signature, were asked to provide two forms of identification and to sign an agreement attesting that they are residents, he said.

Asked in an interview whether he was concerned about the allegations of circulator fraud, D.C. businessman Pedro Alfonso, who is involved in the proposed gaming project, said: "Not an iota. Not one blink of an eye. . . . If there were some renegades out there who decided not to follow procedures, there is nothing we can do about that."

For the most part, Ray said, circulators worked alone to gather signatures. But some circulators were "accompanied by one or more nonresidents to assist them" by telling passersby about the initiative and encouraging them to register their support. In a 20-page response to the challenges, Ray argued that this arrangement is legal under D.C. law, which requires circulators to be D.C. residents but does not "prohibit nonresidents from participating in the petition process."

"The [slots] committee insisted that circulators be District residents," Ray wrote. "If in some instances nonresidents helped, we believe that . . . the board's interest in preserving the integrity of the process was not jeopardized."

Ray also challenged the constitutionality of the city's residency requirement for petition circulators, arguing that several federal appellate courts have ruled that a residency requirement is unconstitutional if it "severely burdens political speech by 'drastically reducing the number of persons . . . available to circulate petitions.' "

The board made no comment on the arguments but agreed to proceed today, following a list of 13 allegations presented by Drake. The first allegation -- that some names and signatures of circulators are illegible on the petition forms -- consumed about an hour of yesterday's hearing as Drake, Brizill, Ray and the three board members studied the challenged petition forms.

Earlier in the day, opponents of the slots initiative asked the board to issue an order against witness intimidation. They said the request was prompted by a visit that the treasurer of the pro-slots committee, Vickey Wilcher, paid to two circulators in Northeast Washington -- a mother and daughter -- in an apparent attempt to get them to change their claims about irregularities during the petition drive.

A Washington Post article quoted the daughter as saying that some circulators had copied names and addresses out of a phone book. "Our witnesses are under a bit of pressure because they will be discussing how they broke the law," Carol Colbeth, legal adviser to DC Against Slots, told the hearing.

Wilcher said she visited the circulators to find out whether their statements in the story were accurate. Wilcher denied that she was trying to get them to change their stories and said she decided to drop by because "I just interact better with people in person."

Ray told the board: "I can categorically say there has been no intimidation of witnesses on our part."

Stopping short of issuing the order, board chairman Wilma Lewis said: "There can be no intimidation of the witnesses. . . . Intimidation is not something we will tolerate whatsoever."

The board said it had received several letters of complaint about the petition drive from District residents.

Board Chairman Wilma Lewis lays down the rules as board member Charles Lowery looks on.Challenger Dorothy Brizill says the petition drive used "fraud and forgery."