killing. there s no question that the suspect knew the trooper was a trooper. he had badge around his neck and marked car right in front of the establishment. reporter: police say trooper brown made his way back inside of the applebee s where he collapsed. he was transported to prince george s county hospital where he died. police say the suspect escaped on foot running across pennsylvania avenue to make his getaway. today officers searched the grounds of nearby apartment complex and even questioned some residents of the apartments. they were checking the area, looking around seeing if anybody fit that description. reporter: police are warning that this is a dangerous killer who needs to be brought into custody. this person dangerous. anybody that would take a shot and kill an armed police officer, guardian of society will have no questions or qualms about harming anybody else who gets in his way. reporter: police say trooper brown was wearing his bulletproof vest a