William French Smith had never dealt with the criminal side of the law until he became attorney general. That helps to explain the low profile he has maintained since he took office: he has been boning up on the criminal side of the Justic Department.

Like Ronald Reagan, Smith has a sure political instinct that adds hardheaded pragmatism to his basically conservative outlook. Perhaps most important of all, Smith has direct access to Reagan, which means that he can count on Reagan's full support.

Here is his plan for the department, as pieced together by my association Bill Gruver:

Smith is determined to make street crime the No. 1 priority of federal law enforcement and intends to develop a closer working relationship between federal and local police forces and to standardize crime prevention and detection methods. He has appointed a Task Force on Violent Crime, made up of experienced law-enforcement officials and headed by former attorney general Griffin Bell and Illinois Gov. James Thompson.

Smith intends to bring his federal prosecutors down to gritty reality. Too often, he believes, U.S. attorneys and other officials have taken "an elitist approach" to their jobs. They have had a tendency to leave the mundane, less glamorous cases to local prosecutors, who are greatly overburdened, Smith feels.

He also plans to strengthen local law enforcement officials by providing them with the resources they cannot afford themselves.

As for his second priority -- the multibillion-dollar traffic in illicit drugs -- Smith plans a broad program to inform and educate students in the nation's high schools and colleges about the perils of drug addiction.

The attorney general has a surprise for those who have been predicting the breakup of the Drug Enforcement Administration and the turnover of its functions to the FBI, the Customs Service and the Immigration and Naturalization Service. On the contrary, he wants to expand the drug agency's duties and to make it leaner and meaner. He will be proposing legislation designed to give DEA more authority -- even though such a move would be contrary to advice he has received from narcotics experts.

Other pionts:

--Constant surveillance of the Ku Klux Klan and similar radical groups that pose a threat to others.

--The Interstate Identification Index, which Smith wants the FBI to establish as a means of improving the exchange of information between the states on criminals and criminal activities.

--Revisions of the Freedom of Information Act to bring it under better control. He has noted that when the act was being passed. Congress was told its administration would cost about $100,000; instead, it has cost more than $10 million since its inception a decade ago.