German authorities have dropped an investigation of a U.S. Army employee who killed a burglar during a home break-in, saying he acted within his rights to defend his family.

Prosecutors said the 41-year-old American fought off three masked men at his Landstuhl home in February, but a fourth pushed past him, ran upstairs to where his wife and three children were and attacked his wife.

Prosecutors say the husband, a civilian employee of the U.S. Army's Regional Health Command Europe, heard her screams, grabbed a kitchen knife and stabbed the burglar twice while fighting with him. The wounded intruder fled and later died.

Prosecutors said Wednesday the American's actions "were justified by self-defense."

Three suspects remain under investigation in the break-in. Authorities didn't release names of anyone involved.