The deceased has been identified as Deepak, resident of Khanpur town in Bulandshahr district, they said.
The incident occurred today when Deepak tried to steal from the house of one Rajveer in Kala enclave. On his entry, the family members woke up and raised alert. The neighbours then came to rescue and brutally thrashed the culprit resulting in his on the spot death, police added.
A complaint has been filed by Rajveer in the matter. Before entering Rajveer's house, Deepak had also stolen a mobile phone from a neighbouring house, they said.