LAWTON, OKLA. — NAS Investment Solutions, a Los Angeles-based investment firm, has purchased Willowpark Apartments, a 160-unit multifamily complex located on the southwestern outskirts of Oklahoma City. According to Apartments.com, Willowpark Apartments was built in 1985 and offers amenities such as a pool, fitness center and onsite laundry facilities. The property consists of 10 two-story buildings on a 6.4 acre site. Units have an average size of 603 square feet. The seller and sales price were not disclosed.