An arrest was made in the homicide of 19-year-old University of Pennsylvania student Blaze Bernstein, the Orange County Sheriff’s Department announced Friday.

Bernstein was last seen Jan. 2 and reported missing by his family the next day. The student was visiting his family during college winter break. Bernstein’s body was found in a California park a week later. Police released minimal details and initially did not say whether they had a suspect or person of interest in the case.

The suspect’s name had not yet been released, though a photo obtained by local news outlets showed a young man in police custody. The Sheriff’s Department planned to hold a press conference later in the day to release details.

Bernstein’s cause of death was not released, though an autopsy was pending. Authorities believed he was killed the same night he disappeared, according to Police Lt. Brad Valentine.

Earlier in the week, warrant documents obtained by the Orange County Register revealed details about Bernstein’s suspected last moments. Police interviewed the friend who drove with Bernstein to the park Jan. 2, who said Bernstein entered the park alone to meet up with another friend. The unidentified friend said it was the last time he saw Bernstein, who stopped answering his messages. The friend said he left the park but came back later in the night.

The friend was also reportedly acting “nervous” and was “talking fast,” “breathing heavy,” and “visibly shaking,” the warrant said. There was dirt under his fingernails and small scratches on his hands, both of which he said came from a “fight club” he belonged to, according to the Register.

The documents also said the friend was visibly attempting not to touch anything and “pulled his jacket over his hand to prevent his hand and fingers from touching any part of the doors he touched.”

It was unclear whether the person in police custody was the friend discussed in the documents, and authorities had not yet discussed publicly the information in the documents.