MADISON, Wis. — The husband of one of four people killed in a string of shootings by a suspect who is Hmong urged community members not to “get caught up in colors” in reacting to the attack.

Nengmy Vang, 45, is accused of launching a rampage that spanned three northern Wisconsin towns on Wednesday, killing his wife’s divorce attorney, a police detective and two people at the bank where his wife worked.

“This person could’ve been any gender, any color, any religion and they could’ve acted in other ways of violence to make their point,” Scott Sann wrote in an emotional letter posted on his employer’s Facebook page. “Don’t get trapped in the details.”

Sann’s wife, Sara Quirt Sann, was the attorney who died in the attack.

According to the U.S. Census, nearly 50,000 Hmong live in Wisconsin. Tensions between them and whites in the state’s northern reaches have occasionally flared, most notably in 2004, when a Hmong hunter fatally shot six white hunters and wounded two more in northwestern Wisconsin.

The Hmong are mainly from the mountain regions of Laos, which borders Vietnam on the west. They began immigrating to the U.S. in the 1970s after the Vietnam War because had had helped the U.S. during the war. They settled mostly in California, Minnesota and Wisconsin.