Software engineer Sumit Kumar, who allegedly killed his wife and three children here last week, has been arrested from Karnataka, police said Wednesday.

On the intervening night of Saturday and Sunday, Kumar had allegedly served sedative-laced drinks to his wife Anshu Bala (32), son Prathimesh (5), daughter Akriti and son Arav (twins aged 4 years) and then slit their throats, police had said.

The bodies were found 22 hours after the incident, following a video posted by Kumar on his family WhatsApp group in which he admitted to the killings. Kumar had said in the video that he will commit suicide and had purchased poison.

Kumar has confessed to the killings, DIG Upendra Agarwal said, adding the accused also told the police that he had purchased knife from a local market.

He said the accused spilled the beans during interrogation after his arrest.

"After killing the family, I changed my clothes and reached the New Delhi Railway station by a taxi and boarded the Thiruvananthapuram Rajdhani Express.

"During the journey, I made a video clipping in the toilet and posted that to my brother. The poison which I had consumed was spurious that is why I survived. I deboarded at Udupi," Kumar told the police during interrogation, according to Agarwal.

After gathering information, the Ghaziabad Police reached Udupi and with the help of local police arrested him and brought him here.

"The knife used in commission of crime has also been recovered. He has been sent to jail. The medical store owner Mukesh Kumar was also sent to jail Tuesday under section 419, 420 IPC and NDPS act," the officer added.

The Ghaziabad police also brought his family here.

Kumar, a native of Jamshedpur in Jharkhand, married Anshu Bala in 2011. He lost his job in December last year.

After being alerted, the police recovered the bodies from Kumar's flat and sent them for postmortem. It was initially suspected that Kumar had purchased potassium cyanide from a medical store in Gyan Khand.

However, medical store owner Mukesh denied that he had sold potassium cyanide to Kumar.Mukesh claimed that he charged Kumar for cyanide but gave him some other sedative.

A thorough search was launched by the drugs department at the medical store but cyanide was not found.

Kumar was a drug-addict and often purchased drugs for his personal use.Due to this addiction, he faced financial crisis and lost his job, police had said.

(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)