DUPO, Ill. – The accused gunman who was in a standoff with law enforcement on Sunday just outside a southern Illinois town had a lengthy criminal history, dotted with dozens of felony and misdemeanor cases.

Around 10 p.m. Sunday, police found the body of Reginald Allen inside the garage of his home in the 700 block of McBride Avenue. Allen, 40, had died of a self-inflicted gunshot wound.

Police claim Allen shot and killed one person and wounded a Dupo, Illinois, police officer earlier that day.

According to Master Sgt. Brad Clossen, St. Clair County Sheriff’s Department, things began just after 1:15 p.m. on McBride and Stolle Road. Deputies were notified of a shooting and found a man, identified as Darryl Mantz, dead in the front yard of a home. Mantz was 46.

Allen is thought to have driven a piece of construction equipment that belonged to his family away from the scene of the shooting. A Dupo officer spotted Allen a short time later and went to confront him. Clossen said Allen shot the officer in the neck and shoulder and used the officer’s patrol vehicle to drive himself home.

Allen barricaded himself inside his home, Clossen said. Police from multiple jurisdictions, including the Illinois State Police, closed down the street for several hours. Late Sunday evening, a SWAT team eventually made its way into the home and found Allen dead.

Next to Allen’s body was an AR-style rifle, believed to have been used in both shootings.

Police have not disclosed a motive for the shooting, but Clossen said Allen and Mantz knew one another.

Meanwhile, the injured officer underwent surgery and is expected to recover.

“Right now, he’s undergone at least one surgery,” said Dupo Police Chief Dennis Plew. “He is in stable condition, but still in very critical condition. The outcome looks good.”

Police have not identified the injured officer, only to say he’s 49 and a 12-year veteran of law enforcement.

“The people that showed up at the hospital just to see the family,” Plew said. “The newly-appointed chief of police for St. Louis showed up at the hospital. We don’t know him. I don’t know him personally. I don’t even think he’s from this area. I just think that just speaks to the respect that we have for one another, and what a huge family and love we have for one another.”

A check of St. Clair County court records shows Allen as the defendant in 32 felonies and 29 misdemeanors from November 1999 until the present.

Records show nearly 20 battery-related offenses, four incidents of unlawful possession of a weapon, multiple drug charges, and four counts of armed violence.

Allen faced a reckless homicide charge for running over and killing a man during a fracas outside an East St. Louis nightclub in 2009.

In that incident, Allen was accused of driving over Anthony Rice in the parking lot of the former City Nights. Prosecutors said Allen, who worked as a bouncer at the club, yelled racist insults at Rice and his brother before throwing a rock at their vehicle. One of Rice’s friends pulled out a pistol and fired shots into the air in response, at which point Allen got into his truck and ran down Rice.

Rice was 23.

Charges were not filed in court until June 2011. Allen eventually pleaded guilty to a lesser charge in December 2015, and was sentenced to one year in state prison. Allen had faced up to six years in prison.

As part of that plea deal, prosecutors also agreed to drop charges against Allen stemming from a 2012 assault case at Miss Kitty’s strip club in the Metro East.

Allen’s family owned both City Nights and Miss Kitty’s.