In recent weeks, several Big Law firms in California have welcomed back attorneys who previously worked with them earlier in their careers.

Los Angeles-based environmental lawyer Tom Van Wyngarden returned to Pillsbury Winthrop Shaw Pittman last Friday, after a stint as a partner with Katten Muchin Rosenman, Pillsbury announced on Thursday.

Van Wyngarden, who represents energy companies in regulatory investigations and related disputes, joined Katten in 2013. He rejoins Pillsbury's environmental and natural resources practices group, which has a total of 39 lawyers and other professionals, according to the firm's website.

"I represent a lot of the same clients that the Pillsbury environmental group and other groups within Pillsbury represent," Van Wyngarden added. "It was really a perfect fit."

Van Wyngarden has also defended multiple Fortune 100 companies against claims involving the release of hazardous chemicals and alleged violations of state and federal environmental laws, and represented clients in connection with regulatory investigations and litigates allegations of workplace safety violations. He said even during his time at Katten, he had the opportunity to work on "some very significant matters" for clients of both firms.

Tom Van Wyngarden of Pillsbury Winthrop Shaw Pittman. Courtesy photo

"My experience in the workplace safety area and administrative litigation was significantly enhanced over the last five or six years," he said, adding that he will bring that experience with him back to Pillsbury.

In a statement responding to Van Wyngarden's departure, Katten chairman Roger Furey said, "Tom is a skilled litigator of great integrity. We very much enjoyed working with him, and we wish him continued success."

Katten also confirmed Friday that it is closing its San Francisco office, as well as its Austin office, as a group of nine partners depart for Baker Botts in those two locations, as well as Houston and Washington, D.C.

The same day Pillsbury announced Van Wyngarden's arrival, Kilpatrick Townsend & Stockton announced that it rehired patent attorney James Cleary in San Diego.

Cleary, who spent the last 13 years at Mintz, Levin, Cohn, Ferris, Glovsky and Popeo, rejoined Kilpatrick Townsend as a partner in its intellectual property group's electronic engineering and software team. Cleary started his legal career at precursor firm Townsend Townsend and Crew, which merged with Kilpatrick Stockton in 2011. He said returning to his former colleagues was "an easy decision."

"Having known and worked with Kilpatrick Townsend attorneys over the years, I am familiar with the firm's collaborative yet creative culture with an emphasis on outstanding client service. That has always appealed to me," Cleary said in a statement.

"The firm's rich multidisciplinary experience and robust resources will be of great benefit to clients," he added.

Cleary focuses his practice on patent law, in areas such as preparation and prosecution of patent applications, rendering of opinions on infringement and validity, licensing, due diligence investigations and strategic counseling.

Mintz Levin did not respond to a request for comment regarding Cleary's departure.

Earlier in the week, Perkins Coie announced that Sarah Piepmeier, a former leader of Kirkland & Ellis' Bay Area patent litigation practice, had rejoined its San Francisco office as a partner.

Piepmeier started her legal career at Perkins Coie as a summer associate in 2002, and then stayed with the firm as an associate through 2006.

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