The main accused in the case, Muneer (35), a former student of Aligarh Muslim University, was nabbed from Bisrakh area in Gautam Budh Nagar in the National Capital Region.
"Muneer, who masterminded the murder, and his accomplice Adnan were arrested by the STF. Muneer was carrying a reward of Rs 2 lakh," IG (STF) Ramkumar told reporters here.
Acting on a tip-off that the two would come to Noida, an STF team arrested them at around 9.30 am following an encounter, he said.
Muneer was involved in a number of criminal activities, including looting Rs 34 lakh from a bank cashier in Bannadevi area of Aligarh in 2014, Rs 31 lakh from a PNB employee in civil lines area there in the same year and Rs 1.5 crore from a cash van in Kamla Nagar locality in New Delhi on November 29, 2014, the IG said.
He has also confessed to looting a 9 mm pistol from the bodyguard of a judge in Gomti Nagar area of Lucknow, he added.
After committing the crime, Muneer went to Nepal, stayed there for some time before coming back to India, the IG said, adding that he was planning to go to Mumbai in two-three days.
Ahmed (45) was driving back to Delhi after attending a family wedding at Sahaspur village in Bijnor district of Uttar Pradesh on the intervening night of April 2 and 3 when two bike-borne men overtook his car and shot him 24 times.
It was Muneer who had allegedly fired at Ahmed and Farzana.
Earlier, four persons -- Rizvan, Tanzeem, Rehan and Zainul -- were arrested in connection with the NIA officer's murder.
Uttar Pradesh police had claimed to have solved the case by arresting Rehan, the nephew of Ahmed's brother-in-law, along with Zainul. After the arrests, the police had contended that a domestic dispute was the motive behind the crime.
