GREELEY, COLO. ? A month ago, prosecutors dropped a second-degree assault charge against a former University of Northern Colorado backup punter accused of stabbing the starter in his kicking leg, saying they needed more time to investigate. On Thursday, they filed an attempted first-degree murder charge.

Mitchell Cozad could be sentenced to up to 48 years in prison if convicted of the attempted-murder charge, as well as a second charge of second-degree assault, the Weld County district attorney’s office said.

District attorney’s spokeswoman Jennifer Finch said a warrant had been issued for Cozad’s arrest, but he was not yet in custody. She did not know where he was but said his bail would be set at $500,000.

Cozad’s attorney, Joseph A. Gavaldon, did not return a call. A man who answered Cozad’s mobile phone number hung up without commenting.

Cozad, 21, of Wheatland, Wyo., is accused of stabbing Rafael Mendoza in his right thigh on Sept. 11 outside his apartment in Evans, a small town adjacent to Greeley.

Arrested shortly after the attack, Cozad, who was suspended from the team and university, was released on bond. Less than two weeks later, prosecutors let a deadline pass without filing charges, saying they needed to investigate further.

Thursday’s decision to file the attempted-murder charge surprised some.

“Based on the facts we’ve heard, it does sound a little over the top,” said Scott Robinson, a Denver defense attorney and legal analyst.

“If it appears he was trying to stab a rival in the leg – a la Tonya Harding – first-degree assault is the most serious charge that is provable,” he said.

But if prosecutors believe Mendoza had foiled an attempt on his life, the attempted-murder charge would be justified, he said.

Finch said that after their investigation, prosecutors felt the attempted murder and assault counts “were the appropriate charges.” She did not elaborate.

Police said Mendoza was attacked from behind after returning to his apartment complex from study hall. The assailant fled, but about 10 minutes later, a liquor store clerk told police that two men in a car matching the description of the getaway vehicle stopped, stripped tape off the license plate and drove away.