A family was in tears on Tuesday as the man who killed their loved one was sentenced to 25 years in prison per a plea deal.Arnulfo Cortez, 35, was driving home in Dec. 2020, when he was fatally shot by Kevin Perez, who fired off rounds indiscriminately during an argument with his girlfriend, San Antonio police said after the incident.Cortez crashed his truck on Loop 410 on the Northwest Side and died at the scene.Perez was later arrested and cha…