The government burned his house. His wife left him and the government provided her with a safe haven in the city. In fact, she turned him in --- ironic since she was the person so concerned about losing their home. He was tracked on television and everyone was put on alert to look for him.
"...watch for a man running...watch for a running man....watch for a man alone, on foot... watch..." (pg 124)
Because the man hunt was being shown on television, they had to have the Mechanical Hound catch him. We know by this point that he has burnt the Mechanical Hound to a crisp. They have to bring another one into the city from another fire department. While he is heading to Faber's house, a beetle (car) tries to run him over. Helicopters are also in the air searching for him. It is known that
"the Mechanical Hound never fails....Tonight, this network is proud to have the opportunity to follow the Hound by camera helicopter as it finds its way to the target." (pg 133)
When he leaves Faber's house, he heads toward the river. The government tells everyone to open their front and back doors and look outside.
"The fugitive cannot escape if everyone in the next minute looks from his house." (pg 138)
Montag jumps in the river, changes into Faber's clothes and douses himself with liquor. Then he floats down the river. The Hound turns around at the river and after a few moments of shining their lights on the river,the helicopters fly away. But the government cannot let the people think that Montag got away. So when he meets Granger, Granger explains,
"The show's got to have a snap ending, Quick! If they started searching the whole damn river it might take all night. So they're sniffing for a scapegoat to end things with a bang. Watch. They'll catch Montag in the next five minutes." (pg 148)
They capture some poor fellow who is out for a walk and kill him. The men sitting around the fire are not surprised. They say,
"Montag is dead; a crime against society has been avenged." ( pg 149)