Jan 22 (Reuters) - A rampage at a ballroom dance venue in Monterey Park, California, that killed at least 10 people on Saturday was one of the most deadly mass shootings in the state's modern history. In 2018, a former Marine combat veteran killed 12 people in a bar in Thousand Oaks. He then killed himself. In 2015, a husband and wife killed 14 people at a workplace holiday party in San Bernardino before dying in a shootout with police. The deadliest shooting in modern California history was in 1984 when a gunman killed 21 people at a McDonald's restaurant...