About John Mario Acosta
John Mario Acosta Jr. built a legal path that began in the classroom and moved quickly into courtrooms. He earned a J.D. from Valparaiso University School of Law in 2015 after completing graduate and undergraduate studies in criminal justice at Troy University, where he received an M.S. in 2012 and a B.S. in 2010.
Early in his legal training Acosta worked across a range of public offices. In 2014 he served as a judicial clerk to William Alexa in Superior Court No. 2 and completed internships with the Lake County Prosecutor’s Office. The following year he took on multiple externships and clerkships, including placements with the Northern District of Indiana Federal Community Defender’s Office, the Porter County Prosecutor’s Office, and the Lake County Public Defender’s Office (Conflicts Division). He also clerked at Bockman & Associates, LLC in 2015.
After law school he moved into practice. In 2016 he opened Acosta Law Office P.C. That same year he worked as a deputy prosecutor in the Porter County Prosecutor’s Office. By 2019 he was serving as Chief Deputy Prosecuting Lawyer at the Starke County Prosecutor’s Office. His work has thus included time as both a prosecutor and as a clinician in public defender and federal defender settings during his training years.
Acosta’s academic background is rooted in criminal justice, and his professional record reflects that. He holds a law enforcement officer certification from the Georgia Peace Officers Standards and Training Council, a credential that speaks to additional training beyond traditional legal study. He has handled matters tied to criminal law from multiple vantage points: as a prosecutor, as a law clerk observing trial-level adjudication, and through defense-related externships.
On the local bar scene Acosta has been active. He has served as Vice President of the Porter County Bar Association since 2015. He held memberships in the Indiana State Bar Association and in regional groups such as the Calumet Inns of Court and the Lake County Bar Association between 2014 and 2018. Those affiliations provided regular contact with judges and practitioners across northern Indiana.
Today he practices as the principal of Acosta Law Office P.C., where his experience in prosecutorial offices and defender programs informs how he approaches cases. He currently focuses his practice on matters arising from the criminal justice system and related litigation in Indiana.
