A teen gunman accused of fatally shooting a Philadelphia community activist during an attempted carjacking while his 2-year-old daughter sat in the back seat has pleaded guilty to first-degree murder and has been sentenced to 35 years to life in prison.

Marvin Roberts entered the plea on Friday during an emotional hearing. Community members and the widow of Gerard Grandzol spoke to the judge about what a good man he was, and urged the maximum for 18-year-old Roberts.

His 21-year-old brother Maurice pleaded guilty two weeks ago to third-degree murder and was sentenced to 25 to 50 years.

Police allege Grandzol asked to get his toddler before they took the vehicle and Roberts, then 16, said "no" and shot him in the face.

Prosecutors say after the shooting, subway surveillance video showed the brothers laughing.