The accused have been identified as Arun, Rockey, Jogendra and Ashish. All of them, aged between 25 and 30 years, are residents of Ghaziabad.
On December 3, they had robbed stamp vendor Sanjay Garg of Rs 19.1 lakh at gunpoint when he was going to his house in Siyani Gate area, along with his colleague. Sanjay was also shot at when he resisted their attempt.
"Police received a tip-off stating that all the four accused were coming to Defence Park area of the district this morning. A trap was laid and all of them were arrested from the spot. They have confessed to their involvement in the robbery," a senior police officer said.
"Police are interrogating all accused and about their accomplices, who would be arrested soon. Police are also scanning criminal records of the accused," he added.