Bill Alter was born on May 15, 1944 in Iowa City, Iowa. After graduating from Parkway school district, Sen. Alter attended the U.S. Navy Electronics School from 1963 to 1965. From 1982 to 1984, he went to Jefferson College Law Enforcement Training Center and since then has gained 22 years of law enforcement experience.

He began his legislative career with Missouri's House of Representatives when he was elected in 1989. In 1993, he was re-elected and completed eight more years of service as a lawmaker. He was elected to the Missouri Senate in 2005.

Sen. Alter currently serves as a reserve police officer, owns a management business and is the vice president of a national company.

He is a member of the Republican Club and National Rifle Association. He is the former president of the High Ridge Rotary, and was the co-founder and former treasurer of the Northwest Jefferson County Chamber of Commerce.

Currently, Sen. Alter lives in High Ridge with his wife Merijo. They have two children: Angela and Brett.