An Illinois man accused of fatally shooting a deputy Thursday reportedly has numerous convictions for armed and violent crimes -- including some offenses involving law enforcement personnel -- as part of a lengthy rap sheet that dates back to the 1990s.

Floyd Brown, 39, allegedly shot McHenry County Sheriff’s Deputy Jacob Keltner in the head at an Extended Stay America Hotel in Rockford where a U.S. Marshals Fugitive Task Force had arrived to arrest Brown on a burglary warrant, police said. Brown fled the hotel in a Mercury Grand Marquis, leading officers on a high-speed chase and then -- while wielding a rifle -- engaging them in a tense standoff before finally being arrested. Keltner, a married father of two, was taken to a hospital where he died later in the day.

ILLINOIS DEPUTY WITH US MARSHALS FUGITIVE TASK FORCE FATALLY SHOT WHILE SERVING WARRANT, OFFICIALS SAY

The original warrant for Brown's arrest Thursday stemmed from a Bloomington burglary, according to NBC Chicago. That alleged offense, however, was only the latest addition to a voluminous rap sheet that stretched back to 1996, the station reported, citing Sangamon County court records.

Brown has convictions in Sangamon County for domestic battery, resisting peace officers, criminal trespass to a residence, aggravated battery of a peace officer or fireman, reckless discharge of a firearm, possession of a firearm by a felon, reckless driving and endangering the life of a child, NBC Chicago reported.

The Winnebago County State's Attorney's Office on Thursday initially issued a warrant for attempted first-degree murder with a $5 million bond that was later upgraded to first-degree murder. Separately, the U.S. Attorney's Office for the Northern District of Illinois, Western Division filed federal attempted murder charges, which are also set to be upgraded, authorities said. The federal charge is on account of Keltner being shot while working on an operation with the U.S. Marshalls. If convicted on a federal murder charge, Brown could face the death penalty, The Chicago Tribune reported.

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Brown was released from prison last January for good behavior.