...that previously kept me from owning a gun ... (Para.2)
previously: ad. before the present time
The ground was so dry that it was difficult to see where the river had been previously. 土太干燥了，很难看出原先河水流经的地方。
The land where the new buildings were built was previously a park. 正在建造新大楼的那块地原先是个公园。
previous: a. coming or happening before or earlier
Sorry! We've passed the street. The previous one was the right one. 对不起，我们已走过了那条街了，前面我们走过的那条街才是对的。
My previous trip out of the country was to Europe. This time I went to Africa. 我上回出国旅行是到欧洲，这回我去了非洲。
He said that during the previous year the company suffered heavy losses. 他说在过去的一年中公司损失很大。