A prominent civil rights attorney is the latest to seek answers into what happened a year ago when a Cincinnati teen became trapped in his family's minivan near his school and died after making two heartrending 911 appeals.

Al Gerhardstein (GEHR'-hard-styn) has recently requested city and police records about the failed response April 10, 2018, to Kyle Plush's calls . The 16-year-old student's chest was being compressed after he was apparently pinned by a foldaway rear seat.

His death led to multiple probes, and to changes in the city's 911 system, training and police procedures.

But the youth's parents have expressed dissatisfaction .

Gerhardstein is a veteran of litigation with city and police who represented the lead plaintiff in the landmark U.S. case legalizing gay marriage.