The accused, Seerat Kaur, who is closely related to a former Congress legislator, was arrested from Mohali town, 10 km from here, Mohali police officials said on Monday.
Seerat has been booked for the murder of her 40-year-old husband Ekam Singh Dhillon. She allegedly used a 0.9mm pistol to shoot him in the head late on Saturday night.
The couple had been married for 12 years and have two children, aged 10 and six years. Their relations had become strained in the past few years.
The couple had shifted to the house in Phase 3B1 of Mohali only 15 days back. Ekam was into property dealing.
The murder came to light on Sunday when Seerat allegedly tried to take away Ekam's body in a large suitcase in their car to throw it into an irrigation canal.
The victim, who was six feet three inches tall, was bundled inside the suitcase with blood coming out of his body.
"She sought the help of a local auto-rickshaw driver in keeping the suitcase in the car. As they were doing so, the auto driver found blood trickling out of the suitcase on his fingers. He left the place and informed the police," a Mohali police officer said.
Before the police arrived on the scene, Seerat had fled as she apparently could not find the keys of the car on time.
Ekam's father, Jaspal Singh Dhillon, refused to cremate the body after post-mortem examination on Monday, saying that the Punjab Police officers were not dealing with the murder case properly owing to Seerat's political influence.
He and other family members of the deceased alleged that he (Ekam) was under stress over the past few months due to strained relations with Seerat.