(Portland Police Department sketch)

PORTLAND, Texas (July 15, 2012)--Police have released a revised composite sketch of a man wanted in a shooting that killed a teenage Texas woman and wounded her girlfriend at a South Texas park.

Mollie Olgin, 19, died in the shooting that left Mary Kristene Chapa, 18, critically injured.

The two were shot on June 23 at Violet Andrews Park in Portland, about seven miles north of Corpus Christi.

Portland Police Chief Randy Wright said Chapa worked with a forensic artist to refine the sketch, which was first released earlier this month.

Police are looking for a man in his 20s who’s white, 5-foot-8, weighs 140 pounds and has brown hair.

The motive for the attack remains a mystery, but authorities have said investigators found no evidence suggesting the women's relationship was somehow involved.

The shooting led to an outpouring of support nationwide, especially in the gay and lesbian community.