He couldn't come to terms with the fact that he was jilted.
Armed with a pistol, the auxiliary policeman from Selangor, Malaysia, went to his former girlfriend's home to confront her.
He didn't see her, but found her brother instead.
The man, 27, fired at the brother, known only as Solomon, in the shoulder before fleeing on his motorcycle, The Star reported.
The drama on Monday happened after Miss Josephine Tholilali Tholan, a 26-year-old factory worker, told the man last Wednesday that she wanted to break up with him.
She said her family had advised her to do so. She told The Star: "We had known each other for about a year and were planning to get engaged.
But my family asked me to leave him because he drank a lot and had a bad temper.
"Since I stopped seeing him, he had been coming to my house every day. On Sunday, he called me up at about 10pm and threatened to kill me. On Monday, he came to the house at about 8.30am."
She said the man fired three shots in the air and demanded that he be let into the compound. Miss Tholan and her 16-month-old nephew were on the upper floor while another six family members were downstairs.
He then climbed over the front gate and shattered the front window using the gun. The man tried to enter through the grilled window but the space was too narrow for him to pass through, she said.