Story highlights Police: Nathan Van Wilkins, 44, is in jail with a $2 million bond

He faces 18 attempted murder charges

Wilkins taken into custody after turning himself in at business 50 miles away

Police say 17 people injured, four with critical wounds

Authorities have charged a 44-year-old man with attempted murder after an early morning shooting at a bar in Tuscaloosa, Alabama, police said Tuesday.

Suspect Nathan Van Wilkins was charged with 17 counts of attempted murder in the shooting, which occurred at 12:30 a.m. Tuesday at the Copper Top bar near the University of Alabama campus, Tuscaloosa Police Sgt. Brent Blankley said. Wilkins also faces another attempted murder charge for a shooting earlier that night in a nearby subdivision, he said.

Wilkins was in the Tuscaloosa County Jail Tuesday night with a $2 million bond, Blankley said.

Police were confident Wilkins was the shooter "based on some of the things he's told us," Police Chief Steve Anderson said earlier Tuesday. No weapon had been recovered, he added.

Tuesday afternoon, the suspect went into a business in Jasper, about 50 miles north of Tuscaloosa, and "indicated he was involved in the incident," Anderson said. He was taken into custody by police there and returned to Tuscaloosa.

JUST WATCHED Bar shooting suspect surrenders at FedEx Replay More Videos ... MUST WATCH Bar shooting suspect surrenders at FedEx 01:51

Surveillance video showed a man walking up to the bar, standing outside for a few minutes looking for someone and then beginning to shoot a military-style assault rifle, Anderson said.

Tuscaloosa police Sgt. Brent Blankley said 17 people were admitted to DCH hospital with injuries related to the shooting. Anderson could not confirm how many of those admitted were shot and how many were injured by shrapnel or flying objects. Of those hurt, he said, one was in "extremely critical" condition, and three others were in critical condition.

Police will work with federal authorities to enhance the surveillance footage, he said.

Eleven shell casings have been recovered, Blankley said. The casings will be compared with those from a shooting that happened in a nearby neighborhood earlier in the evening, Anderson said.

DCH hospital briefly went on lockdown after the incident in order to handle the influx of patients.

Riley Dunn, a University of Alabama senior who was injured in the shooting, told The Tuscaloosa News that 80 to 90 people were in the bar at the time.

"We were all just shooting pool and hanging out," Dunn said. "It was kind of loud from the music, but we heard the gunshot, and no one really knew what to think. The first gunshot took place, then about 20 seconds later, that's when he really started firing them off. After that, everyone really scattered."

Dunn said he suffered a shrapnel-like wound to his leg.

Anderson said three of the people injured during the shooting were students.

Justin McDaniel, who was with Dunn at the scene, told The Tuscaloosa News that the injured left trails of blood outside the bar. He wasn't injured, but his shirt had large splotches of blood on it from running through the bar, the newspaper said.

"We started getting away from the gunshot, like going towards out front, and that's where all the shooting really took place at," one witness told CNN affiliate WBMA . All he could see, he said, were "sparks and people ducking and glass busting. ... We never saw the guy shooting."

Tuscaloosa, about 60 miles southwest of Birmingham, is home to the University of Alabama. The Copper Top is about a mile from campus.