A Missouri man is reported to have lured law enforcement officers to a Baton Rouge business before opening fire on them Sunday morning, sources told WDSU.WDSU reporter Jennifer Crockett said a source at Mayor Kip Holden's office in Baton Rouge told her the information before Sunday's news conference with Gov. John Bel Edwards.MSNBC identified the gunman as Gavin Long from Kansas City, Missouri.The source said the gunman called 911 and lured law enforcement officers to the area before opening fire on them.Louisiana State Police said three officers were killed and three others were injured. Three are from the Baton Rouge Police Department and three are from the East Baton Rouge Parish Sheriff's Office.One sheriff's deputy was killed, one is in critical condition and another suffered non-life-threatening injuries. Two Baton Rouge police were killed and one was injured.Officials said during an update Sunday that the gunman was killed by police. Authorities are asking people to report any suspicious activity.This is a developing story. Stay with WDSU.com for updates.Keep up with local news, weather and current events with the WDSU app here.Sign up for our email newsletters to get breaking news right in your inbox. Click here to sign up!