The live-in boyfriend of Irene Gakwa was sentenced Wednesday to up to six years in prison and ordered to pay more than $13,000 in fines and restitution after pleading guilty to stealing thousands of dollars from her in the weeks after she vanished more than a year ago in Wyoming, according to the Gillette News Record.

At his sentencing hearing, Nathan Hightman was given three- to six-year prison sentences for felony theft and unlawful use of a credit card, the News Record reported. The sentences are set to run concurrently. He was also sentenced to three years of probation.

Hightman, 39, had shared a house in Gillette with Gakwa, a Kenyan immigrant who'd moved to the United States in 2019 to go to nursing school. She was 32 years old when she disappeared in late February 2022, and her family suspects foul play.

Hightman has not been charged in Gakwa's disappearance. He pleaded guilty in March to three financial crimes: one felony count each of theft, unlawful use of a credit card and crimes against intellectual property.

As part of his plea deal, prosecutors dropped two related charges.

Hightman had faced up to 23 years in prison at his sentencing before District Judge James "Mike" Causey.

Hightman told police Gakwa came home one night in late February, packed her clothes in two plastic bags and left in a dark-colored SUV, according to an affidavit of probable cause. He said he hadn't seen or heard from her since.

In the weeks after Gakwa went missing, Hightman withdrew nearly $3,700 from her bank account and spent $3,230 on her credit card, court documents show. Hightman told investigators he withdrew the funds to force her to contact him when she ran out of money following her disappearance.

Investigators said Hightman changed Gakwa's banking account password and deleted her email account.

Gakwa moved from Kenya to attend nursing school in the Boise, Idaho, area, where her two older brothers live. She met Hightman on a Craigslist forum and moved to Gillette with him in July 2021.

Gakwa's family last saw her on a video call on February 24, 2022, and reported her missing about a month later after they could not reach her for weeks via video calls, her favorite form of communication.

In April 2022, Gillette police issued a statement naming Hightman "a person of interest" in Gakwa's disappearance, saying, "He has not made himself available to detectives" looking for answers.

During searches at Hightman's home, investigators recovered a shovel and boots he had bought at a Walmart in late February 2022 using Gakwa's Visa card, according to court documents.

Gillette police arrested Hightman in May 2022 and charged him with the financial crimes. Police have largely declined to provide details about Gakwa's disappearance, citing the ongoing investigation.

For more than a year, Gakwa's family has sought answers about what happened to her.

CNN has reached out to Hightman's attorney and Gakwa's family.