DENVER, FEB. 9 -- A television station helicopter followed a fleeing robber as he killed a policeman and took a hostage today, then dodged bullets as it blocked the suspect's path, enabling officers to rescue the captive and kill the robber, authorities said.

Investigators said the suspect entered the Rio Grande Credit Union about 11:30 a.m., brandished a handgun, demanded cash from a teller and fled seconds later in a four-wheel-drive vehicle.

Off-duty policeman Jerry Wallace saw the suspect fleeing and gave chase, as did a KCNC television news helicopter.

Authorities said Wallace blocked the road with his car and got out in an effort to stop the suspect. Wallace was killed when he was run over by the suspect's vehicle.

A few blocks away, the unidentified suspect lost control of his vehicle. He then fled into a mobile home park, abducted an elderly man identified as John Lauriente and stole the man's pickup truck.

With a television camera aboard the helicopter recording the events unfolding below, pilot Mike Silva followed the pickup and landed his chopper across the road to block it as the suspect fired at his craft.

"After I saw the officer's body flying through the air, I decided this individual was not going to get away if I could help it," Silva said.