Woodbury resident Clayton Robinson Jr., a veteran prosecutor and former St. Paul city attorney, Tuesday announced his candidacy to succeed retiring Washington County Attorney Doug Johnson.

Johnson, the county's chief prosecuting attorney, plans to retire after his current term ends in 2010. He was elected Washington County attorney in 1998.

Robinson said that as an assistant Ramsey County attorney, he prosecuted more than 130 felony jury trials including sexual assault, domestic abuse, child abuse, public corruption and murder cases. He also worked 3 1/2 years as St. Paul city attorney. In 2002 Robinson returned to the Ramsey County attorney's office to serve in his current position as assistant director for prosecutions.

As St. Paul city attorney, Robinson said, he worked in collaboration with Ramsey County Attorney Susan Gaertner to create the Joint Domestic Prosecution Unit, in which both city and county attorneys jointly prosecute domestic violence cases where minor children are present.

Robinson has been an assistant Minnesota attorney general and adjunct professor of law at Hamline Law School. He also operated a private law firm.

Robinson is the son of a Chicago Police Department detective who was killed in the line of duty.