A man was killed and another injured Saturday night after gunfire erupted in a shopping center parking lot amid large crowds gathered near Delaware State University following the university's homecoming events, according to the Dover Police Department.

A security guard and an off-duty Mesa police officer opened fire on an armed teenager outside a private Halloween party early Saturday morning after the teen allegedly shot at the guard when he was denied entry to the event, according to authorities.

A security guard and a customer were critically injured Friday night after an argument over a dog inside a southwest Houston grocery store escalated into an exchange of gunfire, according to the Houston Police Department.