The accused was working as a driver for the victim's neighbour for five to six months, they said.
A man was arrested Wednesday for allegedly killing a 73-year-old woman and fled with her gold ornaments in southeast Delhi's Sarita Vihar, police said.
The accused was identified as Mehboob, 51, a resident of Madanpur Khadar, who had been working as a driver for the victim's neighbour for five to six months, they said.
On November 17, the victim's husband had gone out and when he returned home at around 6.30 pm, he found his wife Savitri Pandey's body on the sofa with her throat slit, Deputy Commissioner of Police (southeast) Chinmoy Biswal said.
The woman was rushed to the Apollo Hospital, where she was declared brought dead, he said.
As part of investigation, CCTV footage of Sarita Vihar as well as adjoining areas were scanned and over 100 people, including family members, maids and drivers, were questioned, the officer said.
Hoping that the elderly couple would have a lot of money and ornaments in their house, the accused hatched a conspiracy to rob them, Mr Biswal said.
Just 15 days before the incident, Mehboob went to the woman's house on the pretext of giving her a letter and conducted a recce.
A few days later, he went to Pandey's home and asked her to lend him Rs 1 lakh. However, the woman refused to lend him money, he said.
On November 17, the accused entered her house at around 5.45 pm, learning that the woman was alone. He demanded money from the woman at knife point, Mr Biswal said.
When she refused, he slit her throat and stole all the jewellery, the DCP said.
However, Mehboob could not take the robbed articles outside the colony, he kept them at a nearby abandoned public toilet and went to his employer's home, he added.