He later attended Frederick Community College, where he earned an Bachelor's degree in criminal justice in 1991.

Prior to serving in the legislature, he worked as an investigator with the Frederick County State's Attorney's office.

He won the Republican primary election with 22.9 percent of the vote, placing second behind incumbent state delegate William J. Wivell.

He also supports tougher sentences for violent criminals and people who commit handgun violations.

[2] In March 2023, Valentine was one of two members of the House of Delegates to vote against the Maryland Child Victims Act, which abolished the statute of limitations for child sexual abuse lawsuits and create a "look back window" to allow survivors to file lawsuits alleging past sexual abuse.