VARANASI/lucknow, May 12 -- An ex-army personnel was arrested on Monday morning following a sensational murder inside a private hospital in Chandauli district, concluding a terrifying 26-hour window during which three fatal shootings rocked the Chandauli-Varanasi region. UP Police launched an investigation to determine whether the suspect is the lone gunman behind all three brazen killings, including two that took place aboard moving trains. "Several CCTV footages have been examined and other evidences collected. From the investigation conducted so far, it appears that the accused was involved in the three incidents. He is being interrogated. Further investigation is on," said Chandauli superintendent of police Akash Patel. The accused, identified as Gurpreet Singh alias Virendra, 45, a resident of Amritsar, Punjab, was overpowered by an auto-rickshaw driver and local residents while attempting to flee the scene of the crime in Chandauli. Police sources revealed that Singh retired from the army in 2020 and subsequently worked as a private security guard in Bihar. Officers recovered two firearms from his possession-one allegedly licenced in his name and another suspected to be illegal. Officials said his background, recent movements and possible connection with the victims are being verified. Police are also examining his mental condition, though no official medical confirmation regarding any psychiatric illness has been made public so far. The most recent incident unfolded at approximately 6:30am on Monday inside a private hospital in Kamlapur, Chandauli. According to investigators, Singh infiltrated the facility by posing as a patient seeking treatment under the alias 'Virendra'. After registering, he proceeded to an upper-floor ward and shot a 55-year-old patient, Laxmina Devi of Bhabua, Bihar, at close range while she lay in bed. The gunshot triggered panic within the hospital, with terrified staff and attendants diving under beds for safety. The assailant fired a second round while trying to flee. "He attempted to escape after the firing, but locals chased and caught him," said the SP. The crowd managed to snatch the suspect's weapon and assaulted him before police officers arrived to take him into custody. Investigators are now working to establish if Singh was involved in two earlier fatal shootings aboard local trains. Hours before the hospital incident, a passenger was shot dead aboard the Kolkata-Jammu Tawi Express near Varanasi in the early hours of Monday. The victim, identified as Dinesh Shah, 42, of Bihar's Gaya district, was travelling to Naimisharanya Dham in Sitapur along with family members on the train (13151). According to police, the incident occurred around 1:40am shortly after the train crossed Pandit Deendayal Upadhyay Junction. Shah had reportedly gone near the washroom area of the S-2 coach when an unidentified assailant allegedly shot him. Passengers alerted railway staff after hearing the gunshot, triggering panic inside the coach. The train later reached Varanasi Junction around 2:42am, where the body was sent for post-mortem examination. SP (GRP) Prashant Verma, along with railway security officials, inspected the scene and launched an investigation. Earlier on Sunday morning, another passenger was shot dead aboard the DDU-Tarighat passenger train in Chandauli. Police identified the victim as Mangru, 35, a resident of Ghazipur district, who had recently returned from Karnataka. Investigators said the shooting took place near Ibrahimpur village shortly after the train left Pandit Deendayal Upadhyay Junction. Passengers told police that two men carrying backpacks had boarded the train and were allegedly involved in an argument with the victim before one of them opened fire. The attackers allegedly threw the body near the railway tracks and escaped after jumping from the slowing train near Tajpur village. Police teams from local police stations, the GRP and RPF are examining CCTV footage, forensic evidence and witness statements to determine whether the three shootings were connected or coincidental....