• Simpson Thacher & Bartlett has announced that Michael J. Osnato, Jr., former chief of the complex financial instruments unit of the Securities and Exchange Commission’s enforcement division, will join the firm as a partner and a member of the firm’s government and internal investigations practice.

• Eckert Seamans welcomes Geraldine A. Cheverko as a partner in the firm’s financial services litigation practice, and Timothy P. Coon as a partner in it’s litigation division.

Kevin Matz has joined Stroock & Stroock & Lavan as a partner in the firm’s personal client services group. He comes to Stroock after maintaining an independent practice for eight years.

Jacqueline C. Charlesworth has joined Covington & Burling in the firm’s intellectual property rights and media and communications practices. She most recently served as general counsel and associate register of copyrights at the U.S. Copyright Office.

Karen Veronia DeFio joins Tully Rinckey as a partner in the firm’s trust and estate planning practice.