The D.C. elections board has been unable to locate about 45 people subpoenaed for hearings investigating allegations that a petition drive to put the legalization of gambling on the November ballot was rife with election law violations, according to city records.

A list prepared by the D.C. Board of Elections and Ethics indicates that the witnesses who could not be found were petition circulators who signed affidavits confirming that they are District residents and had witnessed signatures for the petition drive. A total of 33 people had testified at the hearings by yesterday evening, the seventh day of the proceedings.

In their unsuccessful attempts to find additional witnesses, the board's subpoena servers visited homeless shelters, and residences where the witnesses once lived or never lived. Other addresses included a soup kitchen, a church and a building once used by a drug rehabilitation program.

Slots supporters collected more than 56,000 signatures in a five-day period in an effort to get a slots initiative on the Nov. 2 ballot. The 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.

Elections board Chairman Wilma A. Lewis said that she expects the hearings to conclude tonight and that the question of what to do with petitions signed by circulators who cannot be located will be a major focus as the board begins deliberations.

The board has until Tuesday to rule on two challenges filed by opponents of the slots proposal, and until Aug. 5 to determine whether the initiative collected enough signatures this month to make the ballot.

Board members will also have to decide whether to throw out petitions with thousands of signatures that were signed by several District residents who have testified under immunity that they witnessed few, if any, of those signatures.

"It is important to make sure we have the universe of evidence that would bear on a particular issue," Lewis said.

Board officials said yesterday that they did not know the total number of subpoenas issued for testimony in the hearings. But the board had estimated last week that 70 to 80 individuals could receive the orders.

Anti-slots activist Dorothy Brizill, who filed one of the challenges, said that because the board cannot locate such a large number of people, she has further doubts about "the integrity of the petition process."

"The purpose of giving your address is if the board needs to question you about your affidavit and signatures. So if they can't find these individuals, it is significant," she added.

"The fact that you can't find someone to serve with a subpoena does not mean that they are not a D.C. resident," said former D.C. Council member John Ray, the lawyer representing the slots proponents.

The three-member ethics board ruled Monday that a petition circulator, who must be a D.C. resident, can use out-of-town assistants to pass around clipboards and solicit the public for signatures. But the board also stressed that the circulator must be in control of the process and able to vouch that the signature gathering was done according to election laws.

The board's decision on the key issue comes as members are looking into charges that the petition drive illegally used workers from outside the District to circulate the forms.

Slots opponents have accused many in the effort of forging names and committing other violations of election law.

Ross Williams, who operates his own petition consulting and marketing business in California, testified yesterday for about five hours, answering a battery of questions from the board, the slots opponents and Ray.

Williams said he was brought into the petition drive by another subcontractor to help train District residents hired to collect and witness signatures. Although it was his first initiative drive in the District, he said he did not review the city's election laws or regulations.

Williams also said he told trainees -- about 110 received instruction -- to mention to potential signers that the gambling project would provide more money for schools and health care. Before the drive began, a D.C. Superior Court judge ordered the removal of language from the petition that said the D.C. Council would receive a nonbinding recommendation to spend its share of the slots money "to improve public schools and to help senior citizens obtain prescription drugs."

During the hearing, Williams said that he had flown in about 25 out-of-town petition workers to help with the gaming initiative and that circulators had to reach a quota of signatures to have certain expenses paid, including hotel costs.

Lewis questioned whether there was a "flip side" to the incentive plan that could compel workers to fill petitions at virtually any cost to meet the quotas.

Williams -- who said he was dealing with two other initiatives in Florida via phone at the time of the District drive -- was asked how he and others could have determined whether someone had signed a petition as a circulator when in fact the person had witnessed none of the signatures.

"A crystal ball, I guess," he answered. "There is no way we could have caught that."

Elections board Chairman Wilma Lewis said hearings on the slots campaign likely will end tonight.John Ray, a lawyer for slots proponents, said conclusions can't be drawn about missing circulators.