MILWAUKEE, Wis. (WTAQ) - Milwaukee police say their coordinated efforts against gang violence on the city's south side has netted more than 30 guns, a grenade launcher and nearly 150 people arrested.

It has been called Operation Cornerstone. The grenade launcher was tied to a Greendale home invasion case.

In that incident, a person who was at home at the time was bound with zip ties and duct tape. One person has been arrested and an investigation into the case from Wednesday is continuing.