Forrest was born and raised in Jefferson County. He grew up in Desoto and graduated from St. Pius X High School in Festus. He eventually ventured to the east coast and graduated from Bucknell University in Lewisburg, Pennsylvania with his bachelor's degree in 1990. Forrest earned his juris doctorate from St. Thomas University Law School in Miami, Florida in 1994. While attending law school, he was a member of the honor council and interned in the Broward County Public Defender's Office. Forrest started his law career at Lehnen Law Office in Richmond, Missouri during which time he was also the Assistant Ray County Prosecuting Attorney. In 1999, he returned to Jefferson County as an assistant prosecuting attorney. Then, he left the prosecutor's office and went to work for a local law firm in 2001. After learning the ropes, he eventually hung his own shingle by starting The Wegge Law Office in 2005 and was appointed Desoto municipal judge. In 2006, Forrest was elected as the Jefferson County Prosecuting Attorney and served for twelve years, making him tied as the longest serving Prosecuting Attorney in county history. During Forrest's 12-year term, he taught as an adjunct professor at Jefferson College, chaired various boards and advisory committees, and oversaw the longest student intern program in the history of the Jefferson County Prosecuting Attorney's Office. Once he accomplished the 12-year mark, Forrest became a founding partner at the law firm Wegge & Casey P.C., practicing right on the courthouse square. Forrest currently serves as the municipal judge in Crystal City and resides in Arnold with his wife, Heather, and daughter, Miranda.