CHICAGO – A Maine man wounded in a shootout with police in Union Station remained hospitalized in critical condition and under guard Thursday as investigators tried to determine why he and another man pulled weapons when confronted by police.

The two men involved in a fatal shootout Tuesday at Union Station were wanted in Maine for questioning about a botched burglary in which $30,000 and some guns were taken over the weekend, said Stephen McCausland, spokesman for the Maine Department of Public Safety.

Andrew Ross, 25, of Wells was killed and Daniel Wentworth, 25, also of Wells was injured, McCausland said.

Authorities said a DEA agent, along with Chicago police and Amtrak security, exchanged gunfire inside the terminal when officers spotted a weapon carried by one of the two men.

Police Superintendent Terry Hillard said the Chicago drug task force had been tipped by New York officials, who said two men had paid cash for Amtrak tickets in Syracuse, N.Y. He said police have fingerprinted both men.

The DEA agent emptied his five-shot revolver, wounding one suspect after, authorities said, he drew a .40-caliber semiautomatic. He then used the fallen man’s weapon to kill the second man, who was holding a gun to the head of the Chicago police officer, law enforcement authorities said.

Both men were wearing bulletproof vests and were armed with .40-caliber semiautomatic pistols, Mike Hillebrand of the DEA said. One of the men was carrying $15,000 in cash, he said.

The men had bought tickets from Syracuse to Tucson, Ariz., with a layover in Chicago using fake names, news media outlets reported unidentified sources as saying.

The men were believed to have been involved in the burglary of an antiques dealer Saturday night in Lebanon, Maine, that went awry when a pickup truck with stolen guns and other items was stopped for a routine traffic violation, McCausland said.

Maine investigators declined to say how Ross and Wentworth were linked to the burglary.