CHICAGO (Reuters) – The police hunt in northern Illinois for three suspects believed to be involved in the fatal shooting of a 30-year veteran police officer entered a second day on Wednesday, as local schools were closed and a vigil for the slain officer was planned.

More than 100 officers, including federal marshals, Illinois State Police and McHenry and Lake County Sheriff’s units, have searched by air and ground in dense woods in the area of Fox Lake, nearly 60 miles (97 km) north of Chicago and close to the Wisconsin border.

Fox Lake Police Lieutenant Charles Joseph Gliniewicz was found wounded on Tuesday morning after reporting that he was pursuing three suspects on foot, the Lake County Sheriff’s Office said. He later died.

Officials described the three suspects as two white males and one black male.

Gliniewicz, a father of four boys and a decorated officer, was known around the village as “G.I. Joe” and was dedicated to Fox Lake and his fellow officers, Mayor Donny Schmit said.

He retired as a first sergeant in the U.S. Army Reserve and earned several awards and commendations in the police department, including a medal of valor, a Fox Lake spokesman said. Gliniewicz had also been involved in a youth law enforcement training program for about a decade.

A vigil for Gliniewicz is planned for Wednesday evening.

As police searched, residents were advised to remain indoors and report suspicious activity.

(Reporting by Suzannah Gonzales; Editing by Susan Heavey)

Police helicopters use search lights on the wooded areas for the killers of slain Fox Lake Police Lieutenant Charles Joseph Gliniewicz in Fox Lake, Illinois, United States, September 1, 2015. REUTERS/Jim Young