 Why did the tear gas that the police were using on Mr. Higgins not work to run him out of the house?
There was Mrs. Dolly Daniels, withdrawing money from her savings account again. The third one, who carried a black satchel like a doctor's bag, walked quickly around behind the teller's counter and started filling it with money. The man who had first spoken herded the tellers, Mr. Featherhall and the customers all over against the back wall, while the second man stayed next to Mr. Anderson and the door. Meanwhile, Mr. Anderson went scooting out the front door and running down the street toward the police station in the next block, shouting, "Help! She fell unconscious to the floor, and all three of them ran out of the bank to the car out front, in which sat a very nervous-looking fourth man, gunning the engine. Two police cars came driving down the block and a half from the precinct house to the bank, and the car with the four robbers in it lurched away from the curb and drove straight down the street toward the police station. It was in the crank letter's most obvious form; that is, the address had been clipped, a letter or a word at a time, from a newspaper and glued to the envelope. It happened in Canarsie, a section in southeast Brooklyn near Jamaica Bay. This particular area of Canarsie was a residential neighborhood, composed of one and two family houses. The man who went berserk was a Motor Vehicle Bureau clerk named Jerome Higgins. As the police reconstructed it later, Mrs. Higgins had attempted to awaken him on the third morning at seven-thirty, suggesting that he really ought to stop being so foolish, and go back to work. He then allegedly poked her in the eye, and locked her out of the bedroom. Mrs. Higgins then apparently called her sister-in-law, a Mrs. Thelma Stodbetter, who was Mr. Higgins' sister. Mrs. Stodbetter arrived at the house at nine o'clock, and spent some time tapping at the still-locked bedroom door, apparently requesting Mr. Higgins to unlock the door and "stop acting like a child." At about ten-fifteen, neighbors heard shots from the Higgins residence, a two-story one-family pink stucco affair in the middle of a block of similar homes. Mr. Higgins, it was learned later, had suddenly erupted from his bedroom, brandishing a .30-.30 hunting rifle and, being annoyed at the shrieks of his wife and sister, had fired seven shells at them, killing his wife on the spot and wounding his sister in the hand and shoulder.
 The windows were either broken or open and he was able to throw them back out.
 He was unaffected by the gas because of his deranged mindset.  The windows were either broken or open and he was able to throw them back out.  Higgins was too preoccupied by the burns on his hands to care about the tear gas.  Higgins was hanging out the windows shooting and was able to breathe fresh air.