Acting on a tip-off, the criminals identified as Intezar, Nabia and Nanhe were arrested from near Hapur Adda crossing in the district, they said.
Three uniforms of Delhi police besides two revolvers and large number of cartridges were recovered from them, they said.
The trio used to commit criminal acts including murders in police uniforms in Hapur, Ghaziabad, Bulandshahr, Delhi and Bharatpur (Rajasthan), they added.