KANSAS CITY, Mo. -- A gunman tried to rob a school maintenance worker Tuesday afternoon, police said.

When police arrived, security at Hogan Prep Academy off Meyer Boulevard near The Paseo had already detained the man.

Officers found a gun and took the man into custody, they said.

Investigators with the Kansas City, Mo., Police Department's robbery unit said they were still interviewing witnesses.

They hoped to present a case to prosecutors for possible criminal charges Wednesday, investigators said.