Arizona Cardinals wide receiver David Boston will be charged with misdemeanor DUI, after a recent toxicology screen revealed traces of cocaine and marijuana in his system, a spokesman for the Phoenix Police Department told ESPN.com on Tuesday evening.

A blood test was administered after an incident last month in which a citizen allegedly witnessed the Cardinals star driving erratically, followed him home, and phoned police. Sergeant Lauri Williams confirmed the results of the toxicology screen and said that the matter has been turned over to the city prosecutor's office.

Williams said the tests showed no presence of alcohol. She said that the severity of the sanctions in such a case typically depend on a person's past record and on the discretion of the judge involved in the case.

Boston, 23, is a three-year veteran and arguably the top player on the Arizona roster. He led the NFL in total receiving yards (1,598) in 2001 and earned a spot on the Pro Bowl team. The former Ohio State star was the team's first-round draft choice in 1999.

Neither Boston nor his agent could be reached for comment. The league did not issue an immediate comment on the charges.

Typically in such cases, however, the league allows for due process before levying any potential sanctions. The charges are likely to be reviewed under the league substance abuse policy and Boston could face a fine or suspension.

After a disappointing rookie season, Boston blossomed in 2000, catching 71 passes for 1,156 yards and seven touchdowns. He had 98 receptions and eight touchdowns in 2001. The native of Humble, Tex., is entering the final season of his contract and, barring an extension, would be eligible for unrestricted free agency next spring.

Boston is the son of NFL line judge Byron Boston.

Len Pasquarelli is a senior NFL writer for ESPN.com.