The life partner of a Missouri State Highway Patrol trooper killed on duty in 2009 has filed a lawsuit after he was denied surviving spousal benefits by the Missouri Department of Transportation and Retirement System (MPERS).

In a case that's now on appeal to the state's supreme court, Kelly Glossip has argued there can't be a "gay exception" to survivor benefits for first responders. Lambda Legal and Law Enforcement Gays and Lesbians (LEGAL) are offering Glossip legal assistance.

"Kelly Glossip's partner of 15 years was tragically killed while at work—there cannot be a gay exception to the family protections put in place for police and first responders," said Christopher Clark, senior staff attorney for Lambda Legal. "Missouri has pledged to support its troopers' loved ones if they die in the line of duty, and to deny Mr. Glossip the same treatment is not only discriminatory, it sends a disturbing message to its LGBT law enforcement officers."

Glossip's life partner was Trooper Dennis Engelhard, who was killed on Christmas Day in 2009. Trooper Engelhard was struck by a vehicle while investigating a minor traffic accident.

The Missouri State Highway Patrol provides an annuity payment through its retirement system to surviving spouses.

Engelhard and Glossip had been together for 15 years, according to a Lambda Legal release. They had exchanged rings and owned their home together.

On Dec. 2, 2010, the American Civil Liberties Union sued on behalf of Glossip to challenge the denial of survivor benefits. The trial court granted the MPERS motion to dismiss the case on April 12, and the case is now on appeal to the Supreme Court of Missouri.