Isaac Smith was convicted of killing Karli Short and her unborn child after prosecutors said he feared her pregnancy would expose his secret relationship.

MCKEESPORT, Pa. — A western Pennsylvania man convicted of killing a pregnant woman he had been seeing was sentenced June 2 to two consecutive life terms without parole in the 2021 deaths of Karli Short and her unborn child.

The sentence closed the main trial phase of a case that stretched nearly five years and centered on motive, phone contact, gun evidence and the words Isaac Christopher Smith gave police hours after Short was found dead. Jurors convicted Smith, 30, on May 29 of two counts of first-degree murder. Prosecutors said Smith believed Short’s baby was his and killed her because he feared the pregnancy would upset his life and expose him to his longtime girlfriend.

Short, 26, was shot once in the head in the early morning of Sept. 13, 2021, behind a home off Furnace Alley in McKeesport, about 12 miles southeast of Pittsburgh. She had been staying at her uncle’s home and was pregnant. In court, prosecutors said she had texted Smith two days earlier about a gender reveal party and believed he was the father. Her uncle later told investigators he heard her on the phone asking whether someone was coming to the front or the back of the house before she walked outside and a gunshot rang out.

The case did not begin with a quick arrest. Smith went to Allegheny County Police headquarters later the same day and sat for a three-hour interview, saying he wanted to clear his name. He told detectives he had been intimate with Short and knew she was pregnant, but he denied killing her. Detective Mark Restori later testified that officers initially found Smith convincing. “We totally believed he was telling the truth,” Restori said during the trial. Prosecutors told jurors that later evidence changed the direction of the investigation and tied Smith to the killing.

Investigators focused on the moments before Short died and on the weapon they said fired the fatal shot. Evidence at earlier court proceedings showed surveillance video from a nearby home captured Short walking out a back door at 12:22 a.m. A ShotSpotter alert followed about a minute later. A neighbor found her body later that morning. Prosecutors also presented evidence that Smith had owned a Smith & Wesson revolver and pawned it about two weeks after the shooting. Authorities said ballistic testing matched the revolver to the bullet recovered in the case.

The defense challenged the state’s theory and argued that Smith had no reason to kill Short. Smith told police he was willing to be involved in the child’s life if testing showed he was the father. His lawyers also pointed to the fact that DNA testing later showed Smith was not the father of the unborn child. Prosecutors said that result did not erase motive because Smith did not know it at the time of the shooting. Deputy District Attorney Ryan Kiray told jurors that Short was ready to name Smith as the father and that Smith feared the effect on his other relationship. Short’s family sat through the trial and returned for the sentencing. Her father, Brandon Short, a former Penn State and NFL linebacker, spoke about his daughter as a person, not only as the victim in a criminal case. He said Karli Short had been excited to become a mother and had imagined a future with her baby, who was expected in early 2022. “Karli will not be defined by the man who took her life; she’s defined by who she was,” Brandon Short said after the sentencing hearing.

Smith declined to make a statement in court before he was sentenced. The sentence was mandatory after the first-degree murder convictions, and the two life terms were ordered to run one after the other. The Allegheny County District Attorney’s Office originally sought the death penalty but withdrew that notice before trial. That left life without parole as the punishment after the guilty verdicts. Smith’s lawyers said after the verdict that they were disappointed and would review the case before deciding their next move.

For prosecutors, the verdict confirmed their argument that Smith had tried to hide what they called a double life. They said Short’s pregnancy put pressure on him because his longtime girlfriend had recently met his parents. During trial, jurors heard that Smith told detectives he had not told that girlfriend about Short’s pregnancy. Prosecutors said that silence showed the fear driving his actions. Defense lawyers said the prosecution had built its story around assumptions, not proof, and argued that the later DNA result undercut the state’s claim.

The killing shook McKeesport and drew attention beyond Allegheny County because of Short’s family ties and the facts of the case. Former city leaders and residents had gathered after her death for public remembrance, and her family later supported a scholarship fund in her memory. In court, relatives described the strain of seeing crime scene images, hearing the evidence and sitting near the man accused of ending her life. They also described Short as warm, loving and eager for motherhood.

The criminal case now moves into any post-sentence motions or appeal Smith may file. As of June 19, 2026, Smith has been sentenced to two consecutive life terms without parole, and the next public milestone would be any defense filing challenging the verdict or sentence.

Author note: Last updated June 19, 2026.