Shaheed's associate Satish Malik, whose name also finds mention in the suicide note, however, is yet to be detained.
Kapoor shot himself with the service revolver of his gunman. He had put the barrel in his mouth and pressed the trigger. The bullet exited from other side of head.
"We have registered an FIR under relevant IPC sections of blackmailing and abetment of suicide against both the accused on the basis of suicide note and written complaint also given by deceased's wife," said Sube Singh, PRO of Faridabad police.
As per the FIR, Kapoor was being blackmailed by Shaheed and Malik by threatening him to implicate in a false case. The exact reason of the blackmail is yet to be ascertained.
"We called ballistic and forensic science laboratory experts to collect finger prints, gun powder on the hand of deceased, which will be matched with empty cartridge and other bullets found in the chambers of revolver," Singh said.
"My father was a simple and kind man. He had immense faith in the almighty. He had no enmity with anyone. For the last one-and-a-half months, Shaheed and Malik were mentally harassing him. They were threatening to frame him in a false case, which is why he was stressed," stated Kapoor' son.
In a suicide note, written in English, the DCP said, "I am doing this due to Abdul and Malik. They were blackmailing me and are responsible for my death."
"As per statement of her wife, Kapoor used to go to an Ashram of a spiritual guru once in a week. It will also be examined during investigation," the officer said.
Call records of the deceased are being scanned. The police are also scanning the CCTV footages of his residence to check the entry and exit of visitors.
A case of abetment to suicide has been registered, based on the complaint of Kapoor's son. "My father, as per his routine, would wake up at 5 a.m. Today as well he woke up at that time. Around 6 a.m., we heard a gunshot and woke up from our sleep. He was seated on the sofa in a pool of blood with the pistol in his right hand," the son said.
After the post-mortem, he was cremated on evening.
"With profound grief, we inform you that DCP NIT Vikram Kapoor on Wednesday morning committed suicide at his residence. We are investigating the reasons behind the suicide," Faridabad Police said in a statement.
Kapoor had joined the Haryana Police as Assistant Sub-Inspector in 1983. He was promoted to IPS in 2017. He was posted at NIT Faridabad as the deputy commissioner of police for the last couple of years.
( With inputs from IANS )