Pennsylvania's highest court upheld the death sentence and conviction on Friday of a sniper who killed a state trooper and wounded another in a nighttime ambush outside their barracks in a heavily wooded area.

The state Supreme Court's decision upholds lower court decisions in the case of Eric Frein, who was convicted in the 2014 murder of Cpl. Bryon Dickson II outside the Blooming Grove barracks in northeastern Pennsylvania. Another trooper, Alex Douglass, was badly wounded.

In a 45-page opinion supported by five of the court's seven justices, Justice Debra Todd wrote that the evidence presented at trial was sufficient to support a first-degree murder conviction and death penalty.

The court also rejected several challenges by Frein's lawyers, including one in which they contended that the trial judge violated Frein's right to remain silent and right to a lawyer by allowing the jury to see his post-arrest videotaped interview with police.

After the ambush, Frein led authorities on a 48-day manhunt through the rugged Pocono Mountains before U.S. marshals caught him at an abandoned airplane hangar. The area was briefly transformed, with heavily armed federal agents and police from several states patrolling streets, combing forests and cordoning off neighborhoods

Frein was convicted in 2017. He is on death row, but the most recent execution in Pennsylvania was nearly two decades ago. The state's current Democratic governor has said he will grant a reprieve each time an execution is scheduled until the Legislature addresses problems identified in a report last year. Gov. Tom Wolf has called the system "ineffective, unjust and expensive."