A large gathering started around noon in the south student neighborhood near the 400 block of Lowes Street.
There were 44 medic calls for illness and injury and 18 people transported to the hospital, according to university officials.
Police told the crowd to disperse and later used a loudspeaker and horse-mounted patrol officers to issue more commands for people to leave the area.
Officers used chemical munitions to clear the area after people in the crowds threw bottles at police, according to UD officials.
“There was not one incident that precipitated the decision to clear the street; instead it was multiple factors, including shifting crowd dynamics, increased medical emergencies and safety concerns for the crowd and first responders,” said Savalas Kidd, assistant vice president and chief of police. “Many of those in attendance did leave the area when told; however, some in the crowd resorted to throwing bottles and other objects at officers. This unacceptable behavior caused an escalation in crowd control.”
Lowes Street was cleared around 4:45 p.m. and was closed for the rest of the evening.
About 90 minutes later, Dayton police received reports of disruptive crowds near Brown and Jasper streets.
UD Public Safety officers and Dayton police responded to disperse the gathering.
Around 9:15 p.m. police continued to break up crowds in the area when shots were fired in the Dewey’s Pizza parking lot at 131 Jasper St.
Springboro police responded to the scene, in addition to the Dayton and UD officers.
A suspect, identified as 22-year-old Elijah Murph-Heard, ignored multiple commands to stop fleeing, according to Dayton Municipal Court records.
He ran into the street in front of a Dayton officer, who tried to stop him by knocking him down, a Dayton police spokesperson said.
The collision caused the officer to flip off of the bicycle and injured them.
An officer from another police department also knocked the suspect down with a bicycle, but he got up and continued to run, according to police.
It reportedly took multiple officers to arrest Murph-Heard. An officer used a taser to assist in the arrest, police said.
He had a loaded .380 caliber handgun that was reported stolen in Dayton in 2015, according to court records.
Murph-Heard was booked into the Montgomery County Jail.
He is facing receiving stolen property (firearm), obstructing official business, carrying concealed weapons, having weapons while under disability and resisting arrest charges in Dayton Municipal Court.
The resisting arrest charge is a second-degree misdemeanor.
Brown Street was temporarily closed and students were urged to avoid the area while officers investigated, according to a post on the UD Facebook page.
Police gave an all-clear around 11:30 p.m., and Brown Street was reopened.