Illinois convicted killer Kamron Taylor remains at large after escaping from county jail in the early hours of 1 April, police said.

According to the Kankakee County Sheriff's Office, the 23-year-old overpowered an officer at Jerome Combs Detention Center around 3am, taking the officer's keys and uniform. CBS Chicago reported that Taylor attacked the correctional officer, identified as Deandre Harrington, choked him and beat him unconscious.

"It appears that he somehow was able to get out of the cell, and hid himself somewhere within the facility, in the pod, and then when the opportunity arose, he attacked the officer, beat him, choked him," Kankakee County Sheriff Timothy Bukowski told reporters.

Taylor, wearing Harrington's uniform, then took off with the officer's vehicle and service weapon, which was inside the vehicle. The vehicle, described as a 2012 brown Chevrolet Equinox with Illinois registration P506660, was later found by police.

Police said they were still unsure how Taylor managed to leave the jail, since he would have had to pass through three secured doors and get clearance to leave. "It looks, right now, speculation on my part is somebody didn't do their job properly," Bukowski said.

CBS Chicago reported that a 15-year-old girl, identified as Savannah Bell, went missing and may have been with Taylor. However, police said the teen was later found safe and questioned. Her case was reported as unrelated to Taylor's.

Taylor was convicted on 27 February of the June 2013 murder of Nelson Williams Jr during a botched robbery. During his conviction, he attempted to escape from Circuit Court Judge Kathy Bradshaw-Elliott's courtroom but was quickly rushed out.

The fugitive was found guilty of two counts of first-degree murder and one count each of armed robbery, residential burglary and escaping police. He is now wanted for escape and aggravated battery to a correctional officer.

Taylor is described as 5ft 9in and 171lb. According to the Kankakee County Sheriff's Twitter account, reward for information leading to his arrest has increased to $5,000 (£3,380.53). The convicted killer is considered armed and dangerous.