History records that in the spring of 1638, the Maryland General Assembly "indicted, tried, found guilty and sentenced to hang one Thomas Smith, for piracy." But in 346 years of writing, and sometimes breaking, the laws, the state's representatives have apparently never attempted anything quite like what they are doing to a quiet, aging colleague from Landover, Del. Francis J. Santangelo.

On the legislature's opening day last week, the House of Delegates voted 127 to zero to set up a special investigative committee to consider conflict of interest charges against Santangelo and recommend possible disciplinary action -- ranging from none to censure -- against him. The committee was expected to work quickly and in secret, and report back to the House as early as next week.

In one sense, of course, whatever the investigative committee, and the full House, decide on the Santangelo case will be both significant and precedent setting.

"The real importance of this, "says House Speaker Donald B. Bobertson (D-Montgomery), "is that it will indicate that the House takes seriously its obligation in regard to ethics."

But setting aside all the high talk about responsibility and reform, many legislators are saying that the long, convoluted history of the Santangelo case simply has demonstrated the inadequacy of the ethics law enacted two years ago.

"This guy is catching hell because he's not a lawyer," said Del. Charles Blumenthal (D-Prince George's) on the day of the vote. "He's getting nailed for doing something that a lot of people do here all the time, only they are exempted from the law."

It is indeed somewhat ironic that after generations of blithely ignoring, or covering up, the misdeeds of its members, the legislature should now focus on the case of Santangelo, a slight, 61-year-old insurance broker who, occupying his desk in the House Economic Matters Committee, looks more like Hollywood casting for the loyal organization man, circa 1950, than a modern political manipulator.

The original charges against Santangelo were serious: He was alleged to have attempted to use his office to try to win state contracts for a big band promotion company in which he had an interest in 1976. However, the only charge brought by the legislature's joint ethics committee to the House after nine months of work was that Santangelo had failed to disclose his interest in the Dana Promotions Co. on his 1977 disclosure form.

Meanwhile conflict of interest charges have surfaced against half a dozen different legislators during the time it has taken the ethics committee to investigate Santangelo.

And many legislators have avoided similar investigations -- and sometimes even unflattering publicity -- simply by disclosing their business interests and filing formal statements declaring that their judgment is not affected by legislation that affects those interests. For the legislature's law specifies that a conflict of interest is only an ethical problem when it goes undisclosed.

Moreover, the ethics committee is not the only body that has devoted months to investigating the charge against this inconspicuous three-term delegate. A Prince George's County grand jury considered the allegations over a period of at least eight months in 1979 before issuing a clearance of Santangelo -- and criticizing the handling of the case by the state attorney general's office.

And so Santangelo, having already been investigated inconclusively for two years for actions he allegedly took in 1976, now faces a scrutiny -- and possibly, additional hearings -- by another investigative committee.

"The only thing all this has accomplished is to make Frank sick," grumbled one sympathetic friend last week.

It's not that the charges against Santangelo shouldn't be investigated and, if true, acted upon, some legislative leaders here are saying. Their point is that if the General Assembly is going to take its ethics seriously, it should find a less cumbersome and more comprehensive way to do it.

Sen. Julian Lapides (D-Baltimore), the co-chairman of the Joint Ethics Committee, believes that the ethics investigation procedures will work more smoothly now that they have been used once.

"The problem was that this was the first time," he said of the Santangelo probe. "Every time we took a step, it was precedent setting. So we had to move with great caution in establishing a record of how to proceed."

But Lapides believes in modifying the current practice of having the Joint Ethics Committee, after long investigation, recommend only that another investigative committee be set up. "At the very least the second committee should use the record of the ethics committee rather than putting someone through more hearings, with all the legal expenses involved."

Lapides also believes that the legislature should consider having the ethics committee recommend directly to the House or Senate what actions it should take on ethics violations in the future. The only problem, he says, is that the Joint Ethics Committee is composed of both senators and delegates, "and there may be a constitutional problem with having senators vote on what the House should do to one of its members, and vice versa."

Other legislators are saying that in addition, the ethics law should be tightened so that all cases of misuse of office and conflict of interest -- and not just the isolated exceptions -- come under scruntiny.