The first of six defendants charged for their alleged role in the deaths of 53 migrants in the back of an abandoned tractor-trailer pleaded guilty on Wednesday, the Express-News reports. Authorities accused Christian Martinez, 29, of serving as the middleman in the operation that transported migrants from Laredo to San Antonio between December 2021 and June 2022. He’ll be sentenced in January for two counts of conspiracy to transport undocumented immigrants resulting in serious injury, according to the daily.